I don’t think so. Usually, one doesn’t take a slightly inaccurate screening test and hope to improve the accuracy by repeating it. One moves to a better test. That is true for every screening test I can think of.
I think this is how it would have to work. But they couldn’t do this every day, which is the original scenario. It might be possible to do it once per vacation. But then, there’s the possibility that someone turns positive after the test but before they complete the vacation.
Then there are the personnel and infrastructure required to track all this, which will far exceed the cost of the test itself. I just don’t see it happening at Disney. It’s cost prohibitive.
And IF they did all this, would they get rid of the other safeguards, such as masks and social distancing guidelines set by the state? I don’t think they can.
When you look at how uncommon the disease is, how hard it is to catch at a place like WDW, how unlikely it is to be fatal, and how inaccurate the test is when given to large numbers of people, and the cost of doing so, it’s unlikely this test would play a role at Disney.
I could see it at a one-off event like a meeting or a game, or some of the other things you mention, though.