Just release the fixed mod for now, Turin.
It'll fix the heroes in the existing games. If you release the fully upgraded one later with the same version number, it'll just overwrite the old one and keep the games intact as long as everyone upgrades at the same time, since altering mods will change things on the fly as long as you just restart Dom3.
If the only changes compared to the fixed version are additions of new heroes, it shouldn't even affect much of anything.