Apart from the disappointment the girls whose season is suddenly over must feel, this is a very interesting situation.
As I understand the Ohio season, you have league meets one week, districts next, then regionals, then state. I don't think the league meet determines who goes to districts, but there's clearly some pride at stake in winning the league meet. At least there usually is.
So, there's a distinct possibility of going hard four weeks in a row here. That's a lot. I can understand why a coach might try to game the process a little as the Centerville coach did. After the results of this weekend, though, I doubt very many people in Ohio will be clamoring for a change to the advancement process. Which is too bad, because you could otherwise make a good case for an open weekend between districts and regionals or regionals and state. But I can understand people sticking to a system where a school like Centerville gets their comeuppance.
But, even before it was a matter of hindsight, that coach probably should have thought through a few things more carefully. One, Centerville didn't win their league meet. Surely they knew that was a possibility going in. And, if so, why throw your top kids fully on the line for a meet you may not win, anyway, if being primed three weeks later is the end goal? Maybe part of the problem here is putting too much emphasis on the league meet. Two, you definitely provide a little extra motivation for other teams when you pull your varsity from a qualify-to-advance kind of situation such as the Ohio districts. It's real easy to see how other schools might take this as a bit of rubbing their noses in the dirt and welcome the opportunity to prove you're not as smart as you think you are.
Some people have already said, "Well, just run your varsity at threshold." And that makes some sense. They almost certainly would qualify to advance and without any undue wear and tear unless you have a team member or two who has no concept of gearing it down. You could also split your varsity between weeks, three or four running at league and three or four running at districts. For that matter, you could distribute our varsity across all three weeks of league, district, and regionals, if you're that sure you don't need to full group even to advance out of regionals. In that case, it could be that nobody would even recognize that you're gaming the system.
I understand, in a highly successful program, you want to give your sub-varsity kids a chance to share in some limelight that, if they were running to same times at almost any other school, they'd already have. It is true, though, that if you're not careful, this worm can turn on you. It's entirely possible that a few of the girls could reason, "Well, I won't get to run after this, anyway, so why should I drop everything I've got for someone else to have a chance later?" If that thought spreads--and I don't know one way or the other if it did--you could be in deep trouble in a hurry.
Bottom line: if it's qualify-to-advance, you don't want to leave as much to chance as Centerville clearly did. Centerville is far from the only program around the nation to run a JV team to advance. We'll see what changes other schools in similar kinds of situations make in light of this. The warning shot has been fired.
It is the factor of the unknown that makes sports so interesting.