There are a few people I know IRL who've trooned out, but I was never really that close to them. They were mostly people I shared a few college courses with or met through mutual friends. Of course, my stories are broadly similar to everyone else who posted in this thread: timid, awkward, or otherwise dysfunctional men (and the occasional ftm) on the periphery of a friend group slowly starts to troon out and lose their senses of humour while surrounding themselves with an echo chamber of enablers. I have a few screenshots of their lunacy that I've shared in group chats where we all lamented what they'd become. At the same time though, college is basically an environment where you barely stay in contact with anyone after one semester so it wasn't any real loss to us in the end.
Still, there is one person who got outed for being a predator. What's worse is that this person entered a position of power at Penn State shortly after trooning out. I don't know the specifics behind how he got outed, but I do know that they're still in that position of power at Penn State and that the original confessions website got taken down fairly recently. Sadly, that was my mistake for not archiving it, otherwise I'd share.