> But they have no duty under U.S. antitrust law to provide equal access in the first place.

True, but they're undeniably at a scale where this would just be expected of them either way. We broke up Ma Bell ignoring this exact defense, because at a certain scale of infrastructure you're expected to do the right thing legal or not. If Apple drills down on their "technically legal" defense, they're liable to find out how technically subjective law gets at their scale.