Armory is MPL (Releasing Commercial Products), which I guess is more similar to BSD and MIT. As such I don’t think there should be any problems with neither open source or commercial issues (in other words, you can sell your games) 
Armory (as far as I’ve understood) relies on external tech (Iron/Kha/Haxe), and only the actual blender interface (addon) is supposedly gpl, so your products made with Armory doesn’t have to be gpl