Could be just trolling by them though.

130K people watching and nothing happens XD.

Except for throwing some stars, maybe it is PM?

Fallout 76:

https://www.youtube.com/watch?v=-ye84Zrqndo the trailer if you not saw it.

From wiki

The Vault-Tec terminal in the Citadel lists Vault 76 as a "control" vault, with 500 occupants. The vault was designed to open 20 years after a nuclear war, and was among the seventeen known control vaults, meaning that it was used as a baseline to compare to experimental vaults. It is also mentioned in one of the alien captive recorded logs (no.13) recorded by Giles Wolstencroft, a Vault-Tec official who was abducted while inspecting the vault's construction site. In Fallout 4, the newsreader in the prologue mentions Vault 76 debuting in 2076 in honor of America's tercentenary when discussing Vault-Tec's plans to expand.

So is it a game that takes place inside one of the vaults?

Yeah probably an MP game because it is made by the battle cry devs.

So it's a Fallout spin off but not like the great F3 Vegas??

Some people are saying it's going to be an online based game, while others think it will be a BR styled game. I hope it's neither tbh. I don't mind a spin-off like New Vegas, but this time Bethesda, make sure it actually runs decently. F4 ran like hot garbage for me, to a point where I uninstalled it and went back to Skyrim SE (which runs fine).

Bethesda are so behind when it’s comes to making fully working open world game compared to the European developers CDPR and now GG, those games (The Witcher, HZD) almost ran perfectly out the box especially compared to Bethesda’s games. Plus the worlds they created are so much better with the detail and craft they put into them compared to the elder scrolls and fallout games, which have bland areas and really poor textures, it almost looks lazy in some parts, as if the devs just couldn’t be bothered to put more thought and detail into certain areas where they didn’t expect many players to venture.
Let me make it clear though they arnt bad games and I enjoyed fallout 3 and Skyrim, I just think they should look at the work that those other devs put into their worlds and do a similar job.