Will there be any expansions for Heroes 5?

Add-ons will definitely be included. I haven't seen a single successful game without add-ons, and Heroes 5 is no exception. By the way, regarding the map editor, it should be in a free patch, not an add-on. And an add-on is just another space for creativity. P.S. Moreover, I suggest creating a fan-made add-on. I think this portal is large enough, and if we gather people and offer it to Nival, I think they won't refuse.