He already has, in a talk at the Federalist Society last year, where he said that if given the chance to replace a SCOTUS justice in 2020 he would not hesitate.

EDIT: And again, just over an hour ago, McConnell promised that he would have a vote on a new justice within a week of receiving the nomination.

Meanwhile, Murkowski of Alaska announced she would not support confirmation hearings until after the election.

And in other related news, Senate Democrats have promised to add seats to the Supreme Court if they win the Presidency and Senate in November and McConnell goes ahead with his plans...

The next few months are going to be exciting.