Okay - after some searching... basically the Community AP's were withdrawn after a "request" from Lone Wolf when LW started producing AP packs for sale with HL.
See
threads from 2015. A lot of people weren't particularly happy. I don't use the APs myself, and probably missed all the discussion.
The d20 community page should have put a message saying they weren't available anymore or simply deleted all the links.
I'm guessing that some of the AP's never got produced by LW (like Reign of Winter) or have been bundled into something else that's not obvious to find on the store. The only file that I can find the AP_Bestiary Pack for RoW by the Community.