I have a buddy who is in his late 50s and is massive, hes old school and is a big advocater of coming off everything for about a month or 2 every other year or so. I dont know if theres evidence that coming off everything is really good for you but hopefully someone chimes in and lets us know.
I guess it also largely depends on how hard are you pushing during those higher phases and especially if are you competing and trying to make it to the big league. Even still if someone were to run 12 weeks cycles, restore, repeat years on end I don't see how that continuous roller coaster would be that much more healthier than coming down to normal physiological ranges but with the help of exogenous testosterone.