I think we'll wind up seeing a scaled back version of RER, perhaps only using diesel instead of electric. There are numerous additional track and grade separation projects that are associated with RER, but that aren't directly part of RER, and I think those will continue (Stouffville double-tracking, LSE 3rd track, Burloak grade separation, etc). Many of the service increases, even diesel increases, are predicated on those projects going ahead.
As for Finch West, I think it's safe, as the contract was signed just before the election. Unless Ford wants his own Gas Plants scandal, I think he'll let it go through.