From that thread:
https://old.reddit.com/r/RedditAlternatives/comments/1nzbt8b/reddit_has_banned_rlemmy/ni26gw0/
The sub creator got suspended. Checked the Wayback Machine on their profile reveals they are very vocal about certain political issues in Lebanon (in April 2025, last archive). There is a very high chance of something related to that.
Possibly not related to the fact that /r/Lemmy dealt with Lemmy.
EDIT: Someone in that thread also mentioned that /r/lemmy2 was created in response, so it'll be interesting to see what happens there. If it stays up, probably unrelated to the subreddit being about Lemmy.