I received an email about threads and Mastadon a bit ago. The thing is I deleted my Mastadon account a hot minute after I created it. The email has no way to unsubscribe from it 
I would like to be comforted that I’m overthinking this. My Mastadon account was a couple of years ago in both creation and deletion. It’s incredibly disconcerting.
You can export your mastodon user to other instance. There are plenty of them that have started to block threads.
My post is literally about the fact I don’t have an account there……….
Only looking at the collapsed post I can see why they might think it was about Threads.