I don't think expecting two title defenses per year minimum per weightclass (from a fan's perspective) is unreasonable. Barring extreme circumstances, I think 2 should be mandatory. If you can't stay healthy enough to fight at least once every 6 months, perhaps a career or organizational change is in order.
If Conor holds two belts, that's 4 fights per year, alternating between FW and LW. That alone will take it's toll on his body soon enough.
Even though I think it's utterly ridiculous for the UFC to consider allowing it, and extremely unlikely to happen at all, but should Conor hold 3 belts, that's 6 fights a year across three weight classes. Fighting every second month. 1 injury would then screw up multiple weight classes. 1 ACL tear would hold up three divisions for a lengthy period of time, and create one hell of a clusterfuck trying to set up interim titles and challengers, etc.
Two divisions being in disarray is disastrous enough, but 3 is simply asking for trouble and bad business. Putting the company in that perilous a predicament for the sake of selling tickets and buy rates (at the expense of the divisional stability and Conor's health) would almost warrant some strange twist of fate intervening to teach people a lesson. If for some reason he did beat RDA, I think his ego would really try taking him to 170 next.
I'm giving Conor a 20% chance he beats RDA. He gets a 2% chance he beats Lawler (and that's being generous).