They should have instead fixed their matchmaking so that 3+2 vs. 2+3 match-ups were prioritized rather than prioritizing quicker queue times.
Their "cure" may end up worse than the concern because now they are forcing teams of 1's, vs. 2+2+1 and it's going to be a jumbled, uncoordinated mess.
And that's a separate issue from the problem already raised about teams of 3 and 4.
Only Blizzard knows why they are disregarding what every other MOBA (and a fair bit of multiplayer) games have already had to do to resolve this issue. They're trying to reinvent the wheel here and a significant portion of their decisions are unnecessarily novel.
The matchmaker *does* prioritise matching group sizes, over every other requirement. That's the problem currently - the game cares more about matching my group of 3 with a 2 than it does skill level. This has led to some incredibly unfun, toxic games where according to hotslogs we're being matched with people with 1000 MMR lower than us (who for some reason are always the ones issuing orders, swearing and being toxic).