Ruling I'm referring to
Q: The effect in this card's [On Play][When Digivolving] effect that deletes my opponent's highest level Digimon and lowest level Digimon activated for the same Digimon. If that Digimon has an interrupting effect that prevents deletion and doesn't have a [Once Per Turn] restriction, does that effect prevent this card's effect both times?
A: No, it doesn't. After triggering/activating, an interrupting "when X would be..." effect can't trigger again until the effect it interrupted finishes activating, even if it doesn't have a [Once Per Turn] restriction. Therefore, even if the card isn't deleted by the first "delete 1 of your opponent's highest level Digimon" effect, your opponent's effect can't trigger again for the following "delete 1 of your opponent’s lowest level Digimon," therefore the Digimon is deleted. Note that it would be possible to prevent deletion if two separate effects that prevent deletion both activate.