>But... what about demons/devils?
That's actually why orcs in D&D were an evil race in the first place. At its core, D&D is derived from Lord of the Rings. Orcs in Tolkien's world were created from elves by an evil god/demigod to be his evil army. They had no choice to be good or evil in LotR so that property was inherited into D&D.
I'm okay with this change. Orcs in D&D lore have a different origin than in LotR and I don't see why they should always be evil. I consider this just one more reasonable change from the original game which had odd rules like dwarves can't be wizards and only humans could be clerics.