This is the problem with creating a hard and fast rule. There's always going to be exceptions. So the question is whether it's more important to prevent gym-hopping, or to allow parents and kids to leave a gym in scenarios like this.
I think that for higher level teams, such as Worlds teams, it's probably appropriate to say that once you commit to a gym you have to stay with the gym for the competition season.
But at the lower levels? Maybe the "release" rule needs to be that if you're current financially with your current gym, you are automatically released - but cannot compete for another USASF-sanctioned gym for 60 days. That would discourage blatant gym hopping, but would give kids the opportunity to leave for another gym in these types of situations. And you would only be allowed to do so once per year.