So Grohl & co. did it and a Nirvana "reunion" (obviously without the poor Kurt Cobain) took place during Cal Jam Festival 2018, during the weekend.
Just after Foo Fighters’ own headlining set, Krist Novoselic joined Dave Grohl and Pat Smear for a six-song set of Nirvana classics; Cobain's role of singer was taken by Deer Tick singer John McCauley and punk legend Joan Jett (they both previously took part in Nirvana’s reunion gig following their induction into the Rock and Roll Hall of Fame in 2014).
Watch a fan video of the reunion below.
And this was the setlist:
Serve the Servants (with John McCauley on vocals)
Scentless Apprentice (with John McCauley on vocals)
In Bloom (with John McCauley on vocals)
Breed (with Joan Jett)
Smells Like Teen Spirit (with Joan Jett)
All Apologies (with Joan Jett)