I doubt Disney is currently going to do anything with these mask guidelines. My opinions on what they should do aside, it is just very hard to enforce exceptions in places where people are moving around. Sure you can prove you're vaccinated at the gate, but then every CM you will come across will probably need to see proof again and again and again. They could give vaccinated people wristbands or whatever once they've showed proof of vaccination but still, it'll be extra work.
If they're going to change rules, whether it's masks or social distancing, it's going to be an across the board change. Either everyone or no one.