If people wanted to do it, they would presumably buy two multi-day tickets per person. Yes it’s a big outlay which is why very very few people will bother doing it. But it would probably work and you’d get your money back on the second one or keep it and put it towards the cost of a ticket for your next trip.
To be clear, this won’t allow you to go to more than one park a day, but it will allow you to reserve more than one park a day and decide that day which one to keep.
However, before anyone accuses me of advocating it, let me point out that for it to work you would need to take extra convoluted steps for each person, which would be even more complicated with the reservation system in place.
There is in theory a penalty for an AP no show - three no shows and you’re barred from making further reservations for something like 10 days. Whether they are doing that I don’t know.
The same may well apply to a regular ticket too.
But ,AFAIK, the ticket isn’t cancelled if you don’t go. I have seen trip reports where they just didn’t go to a park on their first day because they were tired, so they stayed at the resort. It’s just a no-show, the ticket remains valid, their remaining park reservations were fine. Whether or not they cancelled the reservation I don’t know, but they only decided that day. So no advance decisions are needed. And because those tickets were extended ones they have an extra unused day on those tickets to use next time (the normal expiry rules are not being applied right now).
And you can change park reservations on the day too.