That is rather odd that the surgeon doesn't have a say in if you are taking T before your surgery. I thought it was normally the surgeon who decided. I went off T for my hysterectomy last year and will never repeat that again. It was even worse when I was in the hospital following complications after kidney surgery and missed one dose, the surgeon had me stay on T prior to the hospital stay and during/up to all three surgery procedures I had in my kidney. All the times I was going for any kind of surgery it was up to the surgeon performing the surgery which drugs were okay to take before, close to, and after surgery.
You're right that you probably won't have a cycle after missing one dose of T, depending on how long you've been on T. When I still had those parts I would get slightly more hormonal during the periods that would have been a cycle and man when I was off T two weeks prior to my hysterectomy was I a raging you-know-what. That was missing two doses since I am on weekly shots. That second week was bad for me and when I was told the surgeon would prefer I stayed off T for another week after surgery I told him there was no way that could work for me. After we talked some more about it and my mental/emotional state the surgeon agreed that the risk for me wasn't very high, not in comparison to my mental health, and that I could start T again once I was home the next day.
As I said before if you are really worried or distressed about this talk to the surgeon (or endo) about it. They should take your mental health and comfort into consideration as well. Remember that if you are going to the endo to get your shots that you won't be able to drive. And unless you have someone who will give you your shot maneuvering around to give it to yourself might be difficult for a few days, perhaps a week.