Park hopping on October 1st

[CarolynFH]

But WHERE does it say that is the policy? I don’t think it does, and it has never been tested. Yes nobody has been denied reentry with a park pass, but nobody has been denied entry with a hopper either. It’s untested ground. So we are just speculating that guests could reenter with a park pass if a park were to get so full it is closed to hopping. My point is just that we won’t know that’s true until we actually see a park get so full that hopping is shut down.

You're right on that - I couldn't find an actual WDW policy statement that re-entry was guaranteed, although it's been stated by reliable sources including Plan Disney, which replaced the Disney Moms Panel and is an official Disney information source, that you can re-enter the park you have a reservation for that day. I do think that because Disney can control attendance by setting the number of park reservations for a given day (e.g. October 1), they're not going to stop allowing guests who have those reservations to leave and re-enter. They're much more likely to suspend hopping to MK that day, which they've made very clear they can do if needed to control attendance. Obviously, we have to wait and see what they do - I certainly don't have a window into their minds!