I bet it's a temporary effect. Like posters here have said their symptoms disappear with they dance. But the effect stops when the dancing stops.

The benefit of dance may also have alot to do with the music. Music therapy alone works for PWP. I think it helps organize the brain.

I doubt that learning dance steps will carry over to daily life in a big way.

BUT, people do walking meditation, where they are conscious of all of their movements. It's as effective as transendental meditation. I think that would be of help to PWP.