We don’t normally wait and program in the departure at this late point, because there is too much to do with coordinating with ATC, ground crews, cabin crew, checklists etc to get away on time. What we do is put in what we expect from the filed flight plan coupled with experience and knowledge of the particular airfield.
says it all really. ATC ground procedural/restrictions having un- foreseen safety repercussions.
Also before I retired the number of readback errors ( not picked up by atc) was increasing. Ie reading back what you expect & briefed rather than what was said.