As I said with Biden, it depends upon what he meant. If he knows who he is going to pick, and it’s a woman, fine. Even, if all the finalists happen to be women, fine.
But if he restricted the search to women, not fine.
Trump says he will not fill the RBG spot if not re-elected, thus motivating more voters to vote for him and maybe de-motivating marginal Biden voters, thus increasing Trump’s chances.
He can always go back on his word if Biden wins. What would he have to lose?