As I mentioned on poa.st, the poa.st and other twitter-style threads could be displayed instead as a Forum thread. I mean, really, it's just a top level reply and then everyone's replying to that top level reply, that data model works both for twitter threads and forum threads. As a bonus, subforums and even forums themselves could just be another "post" in the "thread."
I believe there might be challenges in data loading, but who knows?
I don't know how the Fediverse handles shit when a node dies. Do all of their posts vanish, but the replies survive? Some redundancy could be engineered, perhaps, if people are engineering a Fediverse-Forum-Threadview.