I think it would be nice to have an advanced options checkbox, similar to "Wait For Expansions", that could be used to wait to only match with other players who have paid subscriptions. It could be called "Wait For Subscribers" or something like that. Obviously, it could only be used if you have a subscription.
Reason for this request: it seems all the worst chat offenders are free accounts, who just make new accounts every time they get banned. This would be a useful option to avoid them.