In the June 5th UA they came out with the revised Undying Light warlock subclass, renamed to Celestial. (That's listed in the 2nd paragraph of the document introduction.) Most DMs I know who allow UA material do want the most recent version if there are multiple out there since it often has feedback and balance changes incorporated.
What was the important synergies in the youtube video? We can see if they still work the same (or possibly better) with the revised Warlock (Celestial).
The Celestial gets healing much earlier, but like the original Undying Light version it's a class feature so it's unaffected by the Life Cleric's Discipline of Life which only is triggered by spell.