@joebeone I believe TikTok has said that when the app goes dark in the US, it will just be a page that explains the situation and allows data download. I hadn't realized that was a legal requirement, but seems to fit.
I'm not aware of any competing apps that import that data in order to bootstrap accounts elsewhere, but it might be interesting to see. We've never had such a large test of portability where the service isn't just degraded but completely inaccessible.