Generally, companies don't have to ask unions for approval for anything that is universally beneficial for the union members, obviously no one would say no to improvements. Union contracts are there to stop changes that might be hurtful for the members, not benefits.

Have you participated in a real union somewhere before and read through the bylaws and such?

I have been a member of a union and I know how collective bargaining works.

An employer is never going to give a union a freebie. Just like a union would never give the employer a freebie. Why? Because the very nature of a union involves bargaining over a fixed contract for a period of time.

And every time a new contract negotiation happens the union will want X and the employer will want Y. Why would either side give the other something without getting something in return? That's just bad negotiation.