The scrolls of Revivify, sure, I'll buy are just a player convenience. The skellie bro, no. An entire character, with fully animated cutscenes, is not just a gameplay convenience. He, and by extension his services, exist.
It is also a part of convenience there, just gotta live with that.
Don't mix gameplay mechanics with RP.
/shrug
No, it isn't. Entire, interactable characters, with goals, ideals, and questions, are not non-canonical plot-conveniences. I cannot (reasonably) open a Harry Potter book and just say "Dumbledore didn't exist, anything involving him didn't happen, he's just a plot convenience". That's not how that works.