Since this is about the private FC room.

I got my room more than six months ago and way back when I got it the system was already an place, that if you for any reason loose the room (mainly, if you for any reason loose FC membership) the items will have a grace period to be picked up or they are gone forever. That was informed to me along the purchase of the room so it must have been either on the help text dialogs I need to click through, or in the active help window the private room purchase spawned. It also might have been one of the housing related explanation dialogs one can choose to read. It's reasonable to assume you were informed about this back on the purchase time.

Now other MMOs, I have played quite a few and in every of them, if I have taken a break of more than a month it has been safe to assume I would have been kicked out of the guilds I were in, except I they were guilds with people I also communicate outside of the game. What I'm saying is, taking half a year hiatus with no contact to the guild is enough reason to expect you have no guild when you return.

Neither of this has anything to do with the new house timing concept, which by the way sends you mail in time to come back to the game to secure your house if the time was running out.