Well if he is not going to filibuster but not vote for him. Where is the difference?
1. Gorsuch gets confirmed, the filibuster gets 'nuked,' and is thus unavailable to Senate Democrats should Trump get another Supreme Court pick.
2. Gorsuch gets confirmed, the filibuster remains intact as procedural leverage for Senate Democrats should Trump get another Supreme Court pick.
Those are really Schumer's only two choices right now. Even the usual Senate GOP suspects (McCain, Graham, Collins, Murkowski) are saying a filibuster of Gorsuch is unacceptable. No matter how much Schumer postures, he simply does not have the votes to do much more than wail.