This is a joke, right? Because I'm pretty sure that this would just kill queue times faster lol.
I mean, if a mount dropped after every single match, then you'd always have a 1 in 8 chance to get it. Those are some damn good odds (far better even then the extreme primal mount drops). You'd probably have your mount within a week and would have no reason to queue anymore. If they made it trade-able you'd never need to queue, because the regular PvP community who queue for fun would be selling their extra's on the MB.
I'm all for adding extra rewards to the PvP game modes, but if we're talking about sustainability then the best option is a vastly expanded and overhauled PvP vendor system, not a freebie mount handed out like candy at the end of every round ... Though I'm definitely not going to turn that candy down if they decide to hand it out. Just saying. Everyone has a sweet tooth, right?