After a lot of research I can say no one knows, Ernest who runs and develops it hasn't been heard from, and it may well be dead. Ernest had health issues he talked about last year, and there has been no activity on the Kbin code since last year. No one else has access to do anything with the site. Many people are giving up.

Were the UFC threads specifically on kbin.social? Or just something you accessed through Kbin? A team forked (copied) the code and have been developing Mbin as an alternative to Kbin. You can see servers here, including many that used to run Kbin. That won't help if the UFC stuff was in kbin.social magazines, though. I didn't work out where the UFC content came from.