Same thing, I wanted to point out that you are talking about something bit different and not about exactly on topic, the moment you mentioned medium and advanced threads, because it has nothing to do with Anbu Clothing armor :D

Anyway, for me it's though to tell if that armor is going to be rare, look at the Summer Break armor, it's still there, pops up time to time, not exactly rare, but then again, what is considered rare? once a month event where you can collect? twice a month event? Maybe, maybe, but Summer Break for example was up till two weeks ago or something, when it was for points again.