Just got back into the game for the pvp and I've been thinking this as well for the unranked warzones. Coming from some more competitive games that have this feature for ranked/unranked it just makes sense if your goal is to increase the quality of the matches because you'll have players that: a) want to play that map and b) know how to play the map
Sure you might have longer queue times for certain modes (I for one love huttball) but in the end you'll play more games that aren't steamrolls and you'll end up enjoying more of your time.
In my opinion if they implement unranked pvp filters queue times will actually be the same or better because the longer queue time for a specific warzone will be balanced out by more people coming to pvp because they can play what they want and will stick around longer rather than quitting after a stomp on map they had no interest in.
Also certain warzone queue times won't necessarily go up, because players that queue for specific warzones would fill spots for that players that don't filter who would then go fill another specific warzone and so on etc.
tl;dr gib pvp filters pls, is good for game