That is a very good question. I take it that the Prime Minister had made his decision or at least considered the possibility of a prorogation well before the day it was requested.
If we amend the Standing Orders or pass a resolution having the same effect, the Prime Minister would have to take this into account and plan around it. Actually, it was not an emergency prorogation but a well considered prorogation. I believe the Prime Minister had some goals in his mind, among which obviously changing the make-up of Senate committees. He could have debated this well before, there was no urgency to do that on December 30.