If there was any chance of Pattinson being the DCU Batman I suspect they would have lead with that right out the gate. I don't think there's any incentive for Reeves to change course (there's always money, but Reeves is already a rich guy - plenty of directors have turned down insane paydays) and I cannot imagine them wanting to deal with the controversy of very publicly alienating him.
Personally, I want a complete story out of Reeves and Pattinson and then never see either of them near Batman again. Done and dusted. The fact we will never, ever see Bale again is a huge factor in what will make the trilogy an eternally special affair.