I think it's safe to expect another three episodes along with the ones mentioned. It's just that only three (Destination: Imagination, The Return of the Bloo Superdude, and Goodbye to Bloo) were mentioned by name.
Didn't Craig verify that there are 13 episodes this season at the Con? I'm kind of remembering he did. And being CN's highest rated show before Chowder came along, they'll air all of them if they're at all smart.