Why is Goldbrook only mixed queue?

A bit confusing. I’ve already heard from a couple people that have reported teaming when they just didn’t realize they’ve been playing with no fill. Even if you do fill, you will be matched with people who are already in the lobby doing their own thing. Players will find themselves regularly wandering into the PvP zone, as a solo, just waiting to get ganged up on. Would it at least be possible to change the matchmaking so we aren’t added into groups that have already been in the match?