Sadly, during your absence, we had a melt-down of one of the posters. TeamGirl went full china syndrome on us and deleted all of his posts. He'd done it before, so it wasn't much of a surprise. That was one of the threads that he had started, and thus, it went, too. there were actually several threads that went missing, and frankly, I wish they had not.
As to every thread being marked as "new", I'd say that has more to do with you clearing cache or cookies, than anything the Forum owners/mods did. I have had no such problems.