Hi djc,
Sorry for the lack of reply on this. No legal issues involved - the main reason we haven't created a "Fate Core" forum for Hero Lab yet is that at the moment, our data file authors are focused on other game systems (Shadowrun, Pathfinder and Mutants & Masterminds) and wouldn't be able to give the forum the attention it deserves.
As it stands, if we created the forum, we wouldn't be able to be responsive to users there, which we don't want. We're hoping to change this situation in the future, once we've hit some milestones and are able to give Fate Core the attention it needs to have its own forum.