If this isn't a joke, he and a ton of other people are going to be sued into the ground for this. If it is a joke, then he and a ton of other people are going to be investigated and possibly sued anyway.
Yishan was a member of the PayPal mafia and started working as an eng director at Facebook in 2005, so it's very likely he has F-U money already. This is someone actually exercising the "F-U" part.
I also don't really see what there's grounds to sue on - pretty much all of business is based on taking advantage of undervalued assets and changing control of them so they can be better utilized. Framing it as a long con won't make any friends at Conde Nast, but all the moves at Reddit have (to my knowledge) been by-the-book, legally.
He's talking about actions he says he committed when he was CEO. He could get himself, Sam Altman, Alexis Ohanian, and Steve Huffman all sued for fucking over Conde Nast (i.e. their own shareholders).
If this isn't a joke, he and a ton of other people are going to be sued into the ground for this. If it is a joke, then he and a ton of other people are going to be investigated and possibly sued anyway.