They're not calling it 8* because that might scare people off. But it's the next step above the 7* units.
To entice people to stay, they're giving out several 5* guaranteed summons, and a bunch of other stuff, so it might be fun just to see what you get from the free pull. Plus you might want to look into that "comeback" promo, which I think gives players who haven't logged in for while lots of free stuff.
They know a lot of players might quit with NV, so I'm guessing they will be giving out lots of stuff in the coming days to compensate.
The Perry thing was dumb; she's not a gamer and I didn't really see any interest from her in the game. That died out quickly and we haven't had any IRL colabs since.
Except one last week, where you could fight the 2 producers of the game for 4hrs during the livestream.
Literally, you could only fight them four those 4 hours, so depending on where you live in the world, you may have been working or sleeping and missed it.
Even if you're not interested in grinding etc, I might suggest catching up on the story. Season 3 has some really good music, it's a really different direction from the first 2 seasons.