More thoughts:
Doing this adjustment for the matchmaker could actually DECREASE queue times as well by opening up the total SR spread for a team while keeping it intact for each role. So for example you could (in theory, and if necessary for the matchmaker to create a game) have Diamond DPS, Silver Supports, and Gold Tanks in one match… but the opposing team would have EXACTLY the same configuration.
This gives the matchmaker more latitude to pull in players, without disadvantaging one side or the other with imbalanced roles.
It has some benefits and drawbacks…
One benefit is that lower ranked players get to see how higher rank players work, which should bring match quality up over time as lower ranks are exposed to better gameplay and strategies.
A drawback may be that the match could be frustrating for a higher rank role to get paired with a much lower one (diamond tanks getting silver supports)… BUT the opposing team would be working under the EXACT same condition… so ultimately the match is fair.