I personally dont think so, a fight card like this needs a huge fight and established level champs/great fighters. Nothing against Conor, he has incredible ability to draw numbers and generate interest but he hasnt even defended his belt once, beat two top fighters and just lost. He should without a doubt be on this card as a co main if the fight is Edgar, but in this case it should be a Jones vs ?, GSP vs Lawler, Anderson vs GSP that kind of fight. And I say the same thing if it would be Aldo vs Conor.
Talking more about Aldo vs Conor, this is a huge fight no question and equal to say a Jones vs Rumble, probably even bigger. But why I dont see it as a main event for 200 is that we've already seen this fight a few months ago and ended early, not to mention it was heavily promoted first half of last year and the fight was called off, so I think something new and fresh makes more sense.
That is how I see it.