Any additional insight on MMP’s “costume” policy?

I’m curious if anyone could maybe clarify this policy found on MLB’s website under MMP info. It states no costumes/masks, yet we all see those fans in full astronaut gear.

I ask because I literally love Kyle Tucker, and I’d like to wear a crown and royal cape over the king’s jersey next time I sit in the front rows of right field. I’m not talking full Burger King getup, just your typical cheap props from a halloween store or something.