I don't really think either approach is exciting. Being told "farm fates because lmao" isn't that much more compelling than "hey hand in tomestones cause lmao." And let's be honest, it's not like adding a certain fate or old alliance raid or old raid clear requirement for the quest would've taken them any more time than adding a 1500 tomestone requirement, so they obviously deliberately decided against it as a design consideration, not because they're "lazy."

Personally, I feel like there ought to be something more custom, something more relevant than either of those choices. Both feel a bit soulless and disconnected from the entire concept. Filler.