For Weeks now, I have read again and again that AOTC will be removed when the pre-patch hits, but the mount will still be obtainable until Shadowlands launches.
HOWEVER, in their recent pre-patch survival video, they appear to state it is leaving when the pre-patch comes!
So, when is the mount leaving: Pre-Patch or Shadowlands Launch?
Shadowlands launch
When Azerothâs heroes depart for the Shadowlands, the last vestiges of NâZoth the Corruptor will fade awayâand the âLost Flightâ quest, which rewards the Uncorrupted Voidwing mount, will vanish along with him.
Voidwing is heroic and remains until shadowlands. Its the others like the AH mount that are disappearing on prepatch, i think.
Yeah, but listen to the video I posted- doesnât it sound like itâs leaving with pre-patch?
Yeah that is confusing
I.e. Why Iâm suddenly confused and worriedâŚfigured I still had way more timeâŚat least until Launch
The mount isnât going to go away, itâs going to have itâs drop rate reduced from 100% to 1% just like they do with all the old raids.
The only thing going away is the brutosaur, and people have known about that for months.
No reason to freak out 
Yeah, I noticed this too.
This is kind of what happens when you have large teams with individuals that may or may not be communicating with each other. I was operating under the assumption that I had until Shadowlandsâ launch to get this mount, but now this video is pretty explicitly stating that I have less than a week left to get it.
Honestly, even if we get a blue post confirming that it will be available until Shadowlands, I probably wouldnât believe it. We should both act as if this is the last week to get it. Anything beyond that is just bonus time. Thatâs the safest play to make here.
This is 100% false. You are referring to the mythic Jaina and Nâzoth mounts. The voidwing is explicitly getting removed. This is common with all end of expansion raid mounts that are connected with the AOTC achievement.
Voidwing isnât a drop. Itâs a prestige reward.
The video is confusing because the wording use and when they show certain images
For example, the voice says ⌠âitems will become more difficult to obtain or completely unavailableâ and then mentions the Brutosaur and Void Wing mount.
I would just refer to their original blog post they made regarding what is being removed, as that is more concise.
This is true for the Mythic mounts
But for the Voidwing mount (Heroic Nya), the quest is being removed post Shadowlands, hence the mount is no longer obtainable.
Iâm biased to think ur right because EVERYTHING other than that video has stated itâs here till Launch. But like the other poster, maybe I should just try to get it this week. Just hope they havenât doubled the price or whatever.
The mount doesnât drop from the boss, it is a reward for getting the aotc achievement.
Isnât it actually a quest item that drops which then starts the short quest to obtain the mount?
yes, once you get the achievement 
Even they are sticking around I think, given the expansion delay.
In their blue post, they donât say itâs connected to the achievement:
Upon defeating NâZoth, youâll loot an item that grants you the âLost Flightâ quest, which can be turned in for your Uncorrupted Voidwing.
Everyone agrees you canât earn the achivement in pre-patch, but everything, except perhaps that video, including the blue post by Blizzard, states the drop for the mount will stay.
Iâm fairly sure the prepatch video was made a while ago. I would wager that the original plan was to remove the voidwing with the prepatch.
It will still pop up in the BMAH at times - probably more costly than a carry.
This is correct.
Another reference
While
Ahead of the Curve: NâZoth the Corruptor will be gone in 9.0, you can still obtain
Uncorrupted Voidwing until Shadowlands launches
run circles around the semantics all you want but it still doesnât change the fact that you donât get the quest item for the mount until you get the AOTC achievement, and it is not a drop from the boss.