Why does riot still call us summoners in the alerts?

We're totally still summoners. Gameplay and story are now separate; the Institute doesn't exist in lore, but it does in the game.

because its a thing... THEIR thing. can't say for certain but I think smite and dota call their players something other than player. It's an attempt to immerse the player in the world (even if the world is like a smashed vase at the moment and riots using spit to put it back together)