It's all about milking as much money as you can and I think Conor and the UFC are thinking if he loses again to Nate he can always drop down to 145lbs. If he goes straight to 145 and loses they've lost out on one massive fight/payday.
yep
this one is a win win now for connor
he gets props for getting straight back in
if he loses again
he will move back to 145 with an extra couple of mill in the bank