I would still train my entire body, but things like deadlifts and squats are going to work much larger muscle groups and generate more fatigue, so it is probably not an untrue statement I suppose.
the compound lifts because they stress the body more will produce more HGH
however what you do outside of the gym has way more of an effect. lack of minerals from poor diets and poor gut health will lead to hormone deficiencies and 80% of guys on here have that. that is why any decent test booster contains Zinc and Boron
I’ve heard and read in different publications that test is produced in the legs . Not sure if that was people’s opinions or fact , but I must say when working legs , no other body part has that same pain and fatigue.
Any rise in test from an exercise over another is negligible. Concentrate on the lifts that will help you progress the most and dont think into things like this