Heresy_generator

Also insisting Ukrainians in occupied territory give up their language and culture or face torture and execution.

According to the documentation: Followers, yes; posts, no.

https://docs.joinmastodon.org/user/moving/#export
https://docs.joinmastodon.org/user/moving/#move

These are app permissions for the Threads app; so the app itself will collected all of the personal information from your phone that it possibly can and send it to Facebook regardless of how you limit the amount of data you choose to share with Instagram. The only way to get around this and still use the app would be to use a clean phone and never use it for anything that may generate or collect personal data.