I would definitely wait. Have them get everything done that they can in the fall up until they spray the gunite. Then you can do plaster by April 1st. Sometimes earlier if winter is mild.

Wait, have everything else done, decking, grading, seeding, fence, etc. Plastering ins spring will run no risk of the plaster not curing properly or staining. The 1st 30 days are critical but so are the next so having it open in spring and being able to monitor it will ensure you the best finish

I am in central MD. When we did our pool, they waited to do the plaster until April of the following year. However, they did the gunite, coping and border before December. Let me tell you, even in April, when you're out there brushing the pool twice a day on a 50 degree day you will be cold and your hands will be numb. Enjoy the experience, it's a great time.