Am I missing something? When had he expressed his hatred for unions? As a union man, if he had said something like that it would've pricked my ears. As far as I know, he's said that he doesn't want his employees to feel like they need a union, but wouldn't stand in their way if they wanted one, which is about as good as it gets for a North American business owner.
If this stuff is true then they should unionize immediately. Solidarity Forever
Edit: I'm not going to double down. This was a blind spot for me, maybe because my union is already established and fairly strong, but I'll hold this L and learn from it