According to the Official Sage Advice Compendium:
— Jeremy Crawford (@JeremyECrawford) March 15, 2017
Is there any reason for reprinting EE spells and SCAG subclasses aside from accommodating the AL PHB +1 rule? We adopted SCAG stuff that makes sense beyond FR, spells to make them more widely available
— Mike Mearls (@mikemearls) October 11, 2017
In Xanathar's Guide, we included only the SCAG elements that we wanted to make widely available, especially beyond the Forgotten Realms.
— Jeremy Crawford (@JeremyECrawford) December 18, 2017
@JeremyECrawford So Hex Warrior, the way it is worded has perked up a question for me. Can you have both a bonded regular/magic weapon and a pact weapon gaining the Cha bonus benefit at the same time?
— Chelsea Neal (@HattyDrago) November 14, 2017
— Jeremy Crawford (@JeremyECrawford) November 14, 2017