Did you search for Blluesky before you made this post? If you did you would have found
That said, it’s probably better to have a generic post to collect things in.
Also, if you just search for “Theravada” on Bluesky you should find a handful of good ones.
There are some other members here who have accounts, but I don’t want to post without their permission.
You will also want to look at people’s “Starter Packs”. Here is the one for BuddhaDharma Magazine:
It’s mostly Mahayana, but some Theravada.