Having a separate elo for each role isn't the best idea. If someone gets a role they don't care about they have no incentive to try at all.
https://nexus.leagueoflegends.com/en-us/2018/04/dev-updates-to-ranked-for-2019/
haaaaaaalp1 votesAnd they will be playing at an elo that reflects their play at that role when they don't try at all. Better than having them autofilled somewhere they don't belong.
JRobin311 votesI think the concern in the OP is for lower ranked games. Obviously the change is designed to help Diamond matchmaking.
That said, maybe we'll see players in off-roles try harder if they believe they have a realistic chance against weaker opponents. That would be an incentive to play.
