while I certainly don't know how many, or how much, I can't help but think some kids are damaging themselves, cutting weight. What is it worth? Sometimes we do need to be stopped from ourselves. I'm guessing that is why we have weight regulations. Since winning is always the goal, be it a championship, or just a varsity slot in the line-up, any edge will be considered.
We've all seen that match, where one kid is huge, and questioned the weigh-in. Or, watched with pity, as the team ate, but 1 or 2 didn't. If a matside weigh-in would stop these types of scenarios, why not. It would seem to be self-regulating: equalize the size edge with the ability to go 6 minutes (up to 5 different times a day). It puts the emphasis on wrestling ability, not the ability to recover/rehydrate quickly.