@bumi @SUp3rN0va regarding the federated Twitter work, I interviewed a person who had worked there at the time, and it was a real thing, published here in Polish:
https://oko.press/ucieczka-z-twittera-przyszlosc-mediow-spolecznosciowych
As far as Dorsey killing it, that's coming from people I know and trust who are in a position to know about this. There are probably other sources online, too.
As far as Jack's "decentralization" shtick, I mentioned this in my blog post about BlueSky's faux-decentralization:
https://rys.io/en/167.html#jacks-bs