Rumors about the Burning Crusade release have been going around lately. According to Youtuber Staysafe, a leak was posted on a WoW forum and sent to him that stated the TBC beta would begin in February and that the release is set for May 3rd.
These rumors should of course be taken with a grain of salt as no official Blizzard representatives have given any word on the matter yet, but surveys sent to WoW players earlier in December about the future of Classic WoW give some weight to the rumors.