No, you will not.
As someone who has several alts, i can 100% say that you are completely wrong on several levels on this.
Not only roles are separated but you even cant place masters on new account. One role doesnt affect others at all. Only leaving game affect all roles.
I did it myself and Like I said I know TONS of 1tricks that are high elo on ALL roles even if they just place tank and dps while they are sup mains.
You are correct it is not possible get placed in masters in the first place on a fresh account.
But if you are GM on one role you will get placed masters+ on the other role 
Of course you dont know this as a bronze-diamond smurfer 
And if you say that this is not true I make a video about it show all career profiles and send the link right here to show EVERYONE that you spread misinformations about things in this game you have absolutely 0 idea about.
On this career profiles you can CLEARLY see that they played tons of Mercy for example until they reached 4k+.
Then after that they just PLACE tank and dps and get placed AT LEAST at 3500+.
I saw it many times and even did it myself.
THIS is the definition of manipulation, rigging and lying.
Thank you for this proof.
But only because they previously played non role q seasons. New accounts which played comp after introduction of role q have it completely separated.
Nope Im talking about NEW fresh level 25 smurfs without played old comp seasons etc 
Then my statement is same, you are completely wrong and mistaken, just go to any stream of top500 who buy new account who already climbed on one role. You will see that they clearly start again at 2350± on different role their first placement match.
Try samito for example.
You clearly have no alts as you must know this if you ever used alt accounts.
Go for it but you will only make fool of yourself. Let me add account like that so i can check it and if you are right i will publicly make topic on here how dumb i am.
Oh so I have to show you all the career profiles to proof you wrong? 
Will you admit that you are totally wrong on everything if I proof it to you?
Read previous post i edited it.
Just to clarify what my claim is:
Accounts created after role q was implemented have completely separated role ranks and new accounts starts at same position on role in first placement match. You can buy new account and play only dps in comp and make it to top500. Then if you start playing support you will start at ±2350 again.
Prove me wrong and i will make topic explaining how dumb i was and you were right. Btw i will want to add the profile you speak of to check myself also. It depends on what and how you will show it.
Btw you can see it on samito stream as he climbed to GM and then when he tried different role, he again started in gold. Just one example out of thousands.
Thats a word.
I dont know if you are able to add those players but I make a yt video and go through ALL competitive seasons from the start and show you the stats.
If I show you accounts that have started like this season and played 100 games on support and are 4000+ (On sup) and played only like 5 matches on dps and are 3500+ WITHOUT playing dps before and the account NEVER played on older seasons you will see Im telling the truth.
Of course I cant check WHEN exactly the accounts were made. But if the accounts first comp season was season 27 or season 28 its a hard proof that they were not made before role queue <- you agree?
I probably dont have to add them if you show all their seasons one by one.
But before you waste a lot of time making the video i really suggest to you to check samito streams when he is doing unranked to gm on dps and then on brig i believe. You will see i am right.
I know this. He was stuck on support in low elo once I checked his videos.
But like I said I even know a Reinhard 1trick that never touched dps before and his career is like:
Tank 4300
Dps 3900
Support \
I saw a LOT of those accs.
Well yes, date of when account was made probably makes no difference. Important is if account has play time before role q. But honestly i would prefer accounts made after role q just to be sure 
if you can find one like that
I dont think he was at all, he pretty much climbed with 100% winrate a lot before he lost. I am not home right now, i can check him later to give you exact numbers.
Any chance theyâll get rid of this stupid MMR garbage at some point? Probably not 
Iâve been winning at a 70% winrate as DPS for 10hrs of playtime solo queueâingâŠand I still only get 19 points for a win, lose 24-25 for a loss.
Why? Nothing to do with my play this season, the hidden mmr just thinks I should be a rank lower than I am, so it is trying to force me to that rank.
In that video Iâve linked you to multiple times, Jeff explained that there are difficulties for new accounts. If they have no information for a role you have never played, they will use the MMR from a role you have played to seed you initially at a rank closer to the data they do have for you. Itâs a very clear and statistically accurate thing theyâre doing. He also has explained clearly that they start it with a very high amount of uncertainty. When an MMR has high uncertainty, it can move faster than they allow MMR to move for situations where there is plenty of recent relevant information.
Seeding 4000SR equivalent MMR from Damage role to Tank role makes sense that it would place you in 3500-3900SR. There are only 5 placement games now, so they donât have a ton of data to change based upon. Just because they use the information they have available to take a good guess at what an unknown SR / MMR should be doesnât mean that itâs evidence that there arenât separate values for each role stored. I mean, we obviously have separate SR, why would they keep only 1 MMR?
You keep refusing to look at the information that plainly explains the anomalies you claim are evidence of misinformation, but the developers have been honest and open about things if you only go and look.
Edit: See later response where this was a misinterpretation of what Jeff said.
I donât think that Blizzard is perfect, theyâve made many decisions I disagree with. However in this situation, you are assuming nefarious purposes when there are none.
If all 3 roles are placed at the same time, this will probably be true, but the scenario Lelouch is talking about where 1 role has a very established SR, the other roles will be impacted by that information in the case where there is no data on that account for the other 2 roles. This is consistent with Jeffâs statements in the Seagull interview.
Edit: See later response where this is incorrect.
But other roles are not impacted, they are completely separated if they werent play before role q implementation.
And I am still waiting for that proof from Lelouch, i guess he has some issues to prove it. But I can actualy do it faster to prove my version today 
Jeff did say that theyâll use as much information as they can when theyâre having to guess because thereâs zero history. So in scenarios that there is completely zero history for Comp, then the first placement game for each role will effectively solidify some MMR / SR number for that role. Edit: This is based on Season 18 specific information at introduction of Role Queue.
I think itâs consistent with my interpretation that if someone went and played 200 games in Damage, getting themselves to 4000SR, that this information would be used if they then played the first ever Support placement match on this account. I think they would take the MMR from Damage and use it as an input (not an MMR with high certainty) for the very first Support match, but that would be it. It wouldnât be causing them to be tied together, it would just be an initial hint about the MMR for that first placement match in support.
Unfortunately some of this is speculation and interpretation on my part, but I feel that it is an informed guess based on the information available.
Edit: My guess was incorrect.