Lead dev for Threads makes me cautiously optimistic.
@EposVox "Embrace, extend, and extinguish" is what everyone was thinking Threads would do to the Fediverse. That is, they'd make a better version of Mastodon, everyone would migrate to it, and then they'd close and lock the doors (again). Facebook did this to blogs in the past.
"Eternal September" is what happened when AOL federated with USENET back in the 80s. The platform was utterly flooded with new users who had no clue about USENET social norms, which were subsequently lost.