New game mode Idea

This may or may not have been suggested but have a limited time game mode where the map is reset to be the past summoners rift (easiest to do s4 SR b/c more people probably have that) and make it essentially that you will be able to play in that season of SR. Such as in S4 have 1 smite and old jungle monsters and old baron model and bring back revive and DFG (Rip DFG) and do that to see how some of the newer champs would be in old seasons.