Netflix was well aware of the show’s popularity on social media, as the fanbase was very vocal first in trying to score a renewal and then protesting the cancellation.
There was demand, and CBS Corporation/Pop was apparently willing to make the necessary deals to bring it back to life.
I do have to wonder if the fact that Pop is a cable network rather than streaming service is what convinced Netflix to let One Day at a Time go, although it’s possible there was quite a price tag attached.