I can imagine all sorts of technical points like how the firehose will be load-balanced so as to not overwhelm any instance, or what metadata they should include in their feeds. Meta also has a lot of AI and moderation expertise that could be of benefit to the Fediverse once it grows into an attractive enough target for the troll farms and spambots.

Quite frankly, the sooner that festering cesspool that is Twitter is killed off, the better off the planet will be. If it takes Meta to wean the talking heads like Oprah from Twitter, so be it. It would be better if Oprah set up her own instance, but that's unlikely to happen, media businesses still haven't understood they need to take control over their distribution rather than the easy way of going through big social networks that will stab them in the back when expedient like Facebook deprioritizing media outlets from users' feeds.