your body does stop making its own but there is no clear answer as to whether or not your body loses the ability to restart its own endogenous production. thats how new and also ignored/understudied testosterone hrt is… if you wait a fee years there might be new information or biomarkers that can help answer this question.

there are other things you can do to preserve your bodies natural T production. there are medications that induce it but its not been studied for long term use. there is also another hormone you can take called HCG that will cause your body to continue making test but its difficult to use.

There is a clear answer - that is, it depends. Some people are able to (mostly) recover their own production and some aren’t. Bodies are complicated.