Yep, they started sending out emails a few weeks ago, as they had a 2 year extension on their GIJoe club/con side of things, which means they are now selling off everything, including the equipment behind the running of their conventions... which is kinda sad, as it definitely means they won't be back to do more Hasbro conventions, now that Hasbro look to have given up on theirs (after just one, and they killed off the licensed events to make it possible).
The link to their GIJoe store page - do searches for Botcon or Transformers.