Religion was first something what was introduced in DLC (expansion) and now is standard part of game (what is OK, its maybe most important thing in history when it comes to concicvences) ...
Now we have expansion (which this is, just in 6 parts) whit magicians and vampires ... how long before they become standard part of game. What if they come with Civ 7 new ides of "bringing history and fantasy together" or something like that.
How long when they become a part of the main game? There have been 4 years of development, 2 expansions, and 6 DLC before you got any non historical content. I think you are jumping the shark, while riding a horse here.
Nobody knows what the next game is going to be, when or if there will even be one. And this is not a discussion of any future hypothetical game.
Also it is clear as water that the devs have been extra careful with not adding any non-historical content in the base game. You are literally arguing on the air here.