I had a whole reply typed out and then lost it, but in short I think genocide comparisons are always going to falls short for me because genocide is a modern, industrialized act of violence commited by nation states against peoples, not acts of individualized supermurder.

I have trouble viewing either the sundering or the rejoinings as genocidal for the same reason - that they are so abstracted from anything that could ever happen in real life, and in no way resemble any kind of real life genocide. (But I can see the actions of say, Garlemald, the Allagan Empire or Limsa Lominsa as genocidal,)