It has worked for years in the most popular sport in the world. I think we can figure it out here for high school sports.
I would propose a review every two years, as you won't have JRs leaving for the NFL, like you would in college sports. And for a few other reasons.
There should be a review board for each sport though, right? For example, Carencro baseball football shouldn't get relegated if the basketball team can't compete in 5A. I think a divisions rearrangement would almost certainly have to take place.