If we don’t have birthright citizenship, how will “real” citizenship be decided? One parent? Both parents? 7th generation birthright? Children of naturalized citizens?

I’m probably safe on my mom’s side as they’ve been here forever, but my paternal grandfather was naturalized-which back in the day meant your wife and children were too, except that Dad was born here 4 years before his parents became citizens. Would he have been natural born, or would he have been considered naturalized? I’m sure there are even more complicated situations out there.