They did say something about this if you’re interested:
Article in the post: Overwatch 2 developer blog: Matchmaker and competitive deep dive, part 1 - News - Overwatch
The quote(s) referring to the issue is: “We’ll try to find pairs of similarly rated players in each role when making a match.”
“For support and damage roles, which have two slots, each player will be paired with one player on the opposite team. There will still sometimes be matches with a large range of differently skilled players, but in these cases, the two teams will be more like mirror images of each other.”
Edit:
Personally, not sure if they will succeed this very much, but it sounds like it is a good idea to pair between roles.
One of the comments on the actual post from “Ordo” makes a good mention that SR is not accounted for in the MMR system: