I’m also concerned that defederating from Threads will make more Threads users than Mastodon users.
Already done, and by an order of magnitude at least. (probably many orders, I don't have the numbers at hand)
I mean, some idea of what they might do would be nice.
You can look at their entire history for that. And somewhere in this very discussion some other person has given a very plausible overview of their potential EEE approach. I'll add a link to that comment later when I have time to find it again.
But, I'm starting to realize that no amount of evidence is sufficient for folks who want to federate with Meta, and at the end of the day my freedom ends where yours begins, so although I will continue to advocate for defederation and flee any instance that does not make that choice, I very sincerely encourage you to do you.
The prospect of everyone and our parents using social media that is not completely beholden to Meta is exciting to me.
I firmly believe that hoping Meta isn't going to be the worst possible company they can this time is not the way to achieve that, and is in fact actively working against that future possibility.
I've been alive, adult, and working in IT for the entirety of the existence of Facebook, so I've had a long time to see everything I needed to see about them.