Meta threads will open federation to the fediverse soon, and while this is mainly to mastodon it will still affect lemmy. They are acting like they won’t be evil, but let’s be real this is Facebook when have they ever done that.
This article which has been trending lately explains some of the issues. https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html
This comment here is a simple analogy if you can’t be bothered reading the article. https://lemmy.ca/comment/5702922
How are they going to send targeted ads when not using their platform?
They could masquerade them as posts or embed them in posts. They would be able to track your IP address through the images they serve - kind of like email