They should never do this, if they did they would have to implement something similar to what MechWarrior Online Did where only groups could play other groups. And that is what drove us away as a smaller group constantly running with other 3 and 4 man groups against a solid 8 or 12 man group. You had to play try hard all the time and that gets old quick.
Or they could cause the bigger groups in with the solo queue and that would be even more of a disaster. Some people just want to play a game or two and not worry about getting ROFLSTOMPED by a large group on Comms focus firing every other ship. I have been on both sides of that, Yes being in the bigger group is fun, but even that gets old pretty quick at times, though it allowed you to try out some different builds.
We were initially ecstatic when they said you could have more than three people then when it was actually put into practice it drove a lot of people away who just wanted to play with a friend or two.
Haven't touched Mechwarrior since with friends, only play it solo now when I do.
So even if you force groups only to play other groups it can cause even more lopsided games. Throwing in with a bunch of randoms would be much much worse.
So No, groups of more than three, though it sucks for you and yours, is actually much healthier for the game as a whole.