Here are the candidates as I see it right now anyway
MM Hunter burst
Sub Rogues
Unholy DK damage
Convoke the Spirits (balance version in particular, I play this and definitely think it’s gonna get hit)
Rogue/Ret Kyrian
The Warrior move that doesn’t let you leave the circle (lol)
Prot pally PvP and sustain
Buff candidates:
Warrior damage
Havoc DK
Assassination Rogue damage
Maybe Survival Hunter damage
MAYBE Warlocks though I suspect they’ll wait on Warlocks a bit
oh, don’t worry. i embrace shadow’s nerf as that will mean i can play it without feeling like part of a herd that only plays meta classes. and as for disc, the sole reason they are usable is because of a covenant ability.
holy is…well, trash.
Prot Warriors are at the bottom of the list for nerfs! Very bottom.
Bad news, friend, Blizz likes to start from the bottom. Nothing like kicking a class/spec while it’s down.
I just hope they don’t nerf hunters. They probably will, but I can still hope
I’m betting Ret/Prot Paladin, Marksman Hunter, Subtley Rogue, Arms Warrior and Windwalker Monk. Guess we will see.
Prot pally hands down is the biggest target, their damage is still to high and currently you don’t even need to use their mitigation just self healing which is for sure not intended. DPS wise I bet they let it play out and see how it goes, Unholy DK, SUB rogue, MM prob near the top of the list to be brought down a little.
In fairness Rey paladin is just OP in pvp not PvE
prot warriors need a buff, We honestly feel really squishy
Which is unfortunate, because I always enjoyed playing sub just because of the stealth based theme of the spec, would’ve preferred to just be “more okay than we were in BFA” instead of the OP definitely gonna get nerfed to oblivion version it is now lol
Ret, MM hunter, and a bunch of conduits etc…
As a sub main since Legion I agree. I hate seeing everyone running around as sub these days because its OP. I remember being made fun of when Sub was given it’s “own” type of spec with NIghtblade and Shadowstrike and it was amazing, very rogue like but the damage with meh. Now it’s FOTM and too many scrubs are playing the spec. Go back to being a pirate you plebs lololol
Definitely not Warlocks. They are subpar at everything 
The new Hybrids with only 1 role
That absolutely won’t play out in M+ or in raids and coming from a Brew that could practically AFK tank in prior expansions is rich. You are talking about 1 guy who was able to solo a M0. I guarantee he could do the same on other tanks. Even when prot paladins were considered garbage tier he was doing stuff like that. You are not going to see prot paladins in even moderate level keys not using SoTR and pretending to be a poorly designed Blood DK. It’s a major dps/threat loss to not use SoTR and it will result in 1 shots or near 1 shots at even moderate keystone levels.
Demon Hunters
/Charizard
Nerfed: Prot Pally and Sub Rogue
Buffed: Prot Warrior and Demo Warlock
Honestly, i expect an enhance nerf in the near future. They are one good defensive utility while stunned from being a real spec again and blizzard never seems cool with that. It feels to me like the enhance class designers know exactly what enhance needs, but some supervisor up the chain always smacks the designers down when they try to, say, give SR back.
For pvp: sub rogues, mm hunters, and ret pallies.
Those are the 3 most egregious right now.
Are the nerfs tomorrow or next week?
night fae is more popular though
I don’t disagree that protection paladins will probably be hit… but is this what keeps people up at night? tanks that are good at their job?
All you need to do to fix prot Paladin is reduce word of Glory heals by 50%. The damage is fine