The temple peaks can be lost independently from the balding process. I noticed that Ronald Reagan lost his peaks well before he became an old man but he kept a full head of hair. I also transplanted many full Class 7 balding pattern patients who kept their peaks despite losing their entire head of hair.
The photos below are of two different men. One man is losing his peak on the left side and already lost it on the right side. The second man is a full Class 7 patient who never lost his temple peaks despite losing all of his hair. I transplanted his balding head with 10,000 grafts but never needed to address his temple peaks. The two pictures below is before and after hair transplants.