You’ve described how a scenario in which the rabbits use this behaviour might be unstable, but so what? For any kind of behaviour whatsoever one can dream up a scenario where animals over or underuse it and subsequently have to change.
Prima facie there’s nothing at all implausible about a stable situation where rabbits use that behaviour some of the time and it makes the foxes give up some of the time.
You’ve described how a scenario in which the rabbits use this behaviour might be unstable, but so what? For any kind of behaviour whatsoever one can dream up a scenario where animals over or underuse it and subsequently have to change.
Prima facie there’s nothing at all implausible about a stable situation where rabbits use that behaviour some of the time and it makes the foxes give up some of the time.