I imagine it will go the way of the brilliant strategic innovation a few years back of shifting defenders heavily depending on the batter's statistical hitting patterns. It'll get banned because it makes the game more boring. If home runs happen all the time, they lose their excitement. I imagine it's quite expensive or impossible to shift the outfield walls back farther in most MLB stadiums.
I actually would love more of a no holds barred evolutionary battle in the MLB [1] but I know it's not gonna happen.