Unbreakable said:
I still don't see why we make an exception for Archer when all the other Fate/Stay Night characters get spoiled, though I seem to be alone in thinking this.
Unlike most of the other characters whose real names are only important "in universe" because they reveal weaknesses or such, Archer's true identity is a pivotal plot point of an entire series (Unlimited Blade Works).
I don't think it'd be super dramatic if we did change his tag to keep consistent with the rest, but imo even if F/GO outright spoils his name I think he in particular should keep his tag spoiler-free. Even nowadays, not everyone who gets into Fate does so through the mobile gacha game.