what about, instead of having the usual 3vs3 soloqueue bracket, we can have for next seasons and onwards a: Soloqueue 5vs5?
here me out!

what if people can have the ability to rotate in between 3vs3 and 5vs5 soloq team formats?
soloqueue 3vs3 has already it's own random matchmaker system, so it wouldn't be that difficult to implement and have the same kind of format for a 5vs5 match. (usually you can go 4 dps - 1 healer or 2 healers - 3 dps), in top of that, since both blackrock-icecrown-lordaeron are connected for matchmaking, there should never be an outage of players queueing non-stop.

as for the matter of avoiding players in case of toxicity, i would just keep it as well as 3vs3. only 2 people at the time.

with being that said, pvp enjoyers should have a new fresh of air with trying something different and somewhat fun. i've brought this idea since i have never experienced to play 5vs5 even once. however it might also solve well-known pvp issues like, not having that many 3vs3 representation up to the point of having no people playing actual 3vs3.