GDPR violation.
No chance they will block out the entire EU market. They will probably just do the same as everyone else and make a specific EU policy.
Actually I think Meta Threads is still not available in EU for the same reasons.
The company said that it will still have opt-out controls in “select countries” without specifying which ones. It mentioned in a blog post that users won’t see more ads but they will see better-targeted ads following this change.