Board Thread:General Discussion/@comment-37194541-20190904195001/@comment-90.253.69.231-20190904195831

Pre emptive blocks are allowed, although they're sometimes controversial. Some admins are friends with admins on other wiki and will share intelligence with one another, and may block sockpuppets who are known to sockpuppet on each wiki, for example.

So overall, no it's not unheard of, but it can be seen as controversial.