People are asking how can Disney check that you are vaccinated. To me, that's not the point of the CDC guidance. It's not to give you a way to prove to another entity you don't need a mask and might could fake it. It's about "proving" to yourself that it's safe to do something. So the CDC has now told you that this is the way to make sure you're safe at Disney or anywhere else.
The purpose of the mask mandate at Disney is to make sure they are doing everything in their power to keep you safe. If the CDC has said, you're safe if you get a vaccine, there is no point for a mask mandate any more in my opinion. I went online to make an appt for my 13 year old today at a Walgreens. There are 10 in my town and all had 20+ appointment spots for TODAY. If you want a vaccine, you have had every opportunity to get it at this point. Only the under-12 crowd can't get a vaccine at this point and we know their level of risk is extremely low, but certainly you can still have them wear a mask or even not come if you feel like there's too much risk. It's now a matter of personal responsibility for your health and risk and time for companies to follow the science and guidance and stop mandating things.