How about after Ward fights Bute and Dirrell, he moves up to LHW and rematches Dawson, so we can know how much of Ward's victory was him being better, and how much of it was Dawson being weight-drained?
Chavez blew out Mayweather at 130 and yet rematched him at 140 so anythings possible (the 140 lb. fight was surprisingly competitive)
If Ward eventually moves up and Dawson is still the best and lineal champ at LHW, I see no reason why not. If this scenario does play out, Ward will have likely fought at 168 for another couple fights, moved up and beaten a titlist other than Dawson at 175; along with Dawson defending his lineal title several times while looking good, hopefully once against Pascal. I wouldn't want to see it for another 18 months at the very earliest if the above situation happens.
Right now there is no interest in a rematch, Ward proved he was superior and no one is going to want to see it again. If in a couple years if Dawson is still the top guy at 175 and has knocked off some of the other top guys like Pascal, Cloud, Campillo etc and Ward moves up to 175 then its possible. If Dawson has re-established himself as a top 10 pfp guy and with it being at 175 then it could probably be sold but for the immediate future forget it.