Clubs would never go for a divisonal system that includes pro-rel. Theres commercial considerations beyond TV that contribute just as much to the coffers of clubs if not more, and you'd be asking half a dozen clubs to give up fixtures against top clubs that they can sell to members and supporters - even if they are rubbish against them.
The "giving up fixtures" is a factor, admittedly. You would lose guaranteed derbies, anzac days and queens birthdays for instance. It is unlikely to happen on that basis alone. More broadly it probably takes too much imagination (if not for the AFL and clubs, for the notoriously reactionary supporter base they'd need to sell it to) to see the merits and opportunities relative to the perceived costs and risks. The AFL haven't even been able to get 17-5 up, and this goes much further
If you did it with the current 18 teams (with two divisions of 9 and 9) you would be able to preserve those fixtures somewhat....that is, each team would play the teams in their own division home and away and have two games against the other division. If, say, the Power and the Crows ended up in opposite divisions they could play eachother twice anyway (which would be imbalanced) or play each-other once and the second game would be against a team that qualified in the counter-balancing position (i.e. 1st -10th, 2nd - 9th etc)