What was the criteria used to choose which SCAG subclasses were to be reprinted in XGE?

@mikemearls @JeremyECrawford What was the criteria used to choose which SCAG subclasses were to be reprinted in XGE? And are they unchanged?

— Li Shenron (@Li_Shenron) October 18, 2017

Is “PHB+1” rule not a factor? We consider that rule when we make such decisions.

— Jeremy Crawford (@JeremyECrawford) October 18, 2017