first of all I’d like to say that i’m very concerned about my online privacy. However what you ask is, with all due respect, delusional.
The only way to prevent this is by moving in closed gate environment where you know the participants. It is impossible to stop all the scrappers or the AIs by posting #nobots. This game is already over and you just consume your mental energy fighting a lost war.
The moment you are posting something online publicly it will be scrapped by unlimited companies. Consider it a fact. Even if lets say the biggest of companies due to public relations reasons, respect such tag, there are unlimited other smaller companies/entities/whatever that will give no fuck at all. If they scrap it, then they can even sell it to the larger companies and your data is again there. It is unpreventable. It is like going in from of other people and telling them “don’t look, look away”. Ok so what, they have already looked and they look again when you turn away.
meta (threads) will not support fediverse already. They said they will do in some later version. So for the completely practical part, you don’t need to do anything right now.