I think a number of people who are content to go with masks but are waiting for their kids to be vaccinated before they go maskless will probably cancel their trips. I know someone who did that who had a June trip and canceled it when the mandate was lifted.
The case levels right now do make a case for lifting it, I just think that it's going to be divided on who's happy and who's not, and the attendance difference will probably be a wash from the mask situation alone. What will make a difference though is that attendance is going to start to go up because of two factors - The resumption of international travel, and the ability of parents to vaccinate their kids.