Presidential appointments can be derailed through filibuster or through refusing to schedule hearings in the appropriate committee or through anonymous holds by a single Senator. All those are allowed through Senate rules, and if one of them is unconstitutional then everyone of them should be unconstitutional.
So does rules mean time, place, etc...in other words, what we consider as Robert's Rules or does rules mean that theoretically, next year, they can change advise and consent to a 3/4 majority vote.