the fact that some of them were done 40 years ago doesn't make the results incorrect. And no, just opened one of the first links in google and it says "in rats, monkeys, and man"
you're making just absurd arguments. I can show you studies saying it does desensitize, but can you show me something saying It doesn't? I don't think so.
Moreover I closely know one of the most respected doc in Eastern Europe and his specialization is the recovery of professional athletes after steroid cycles. And he showed a lot of results after high HCG doses administration, that prove the same point. The same way works gonadoreling suppressing LH and FSH, Actually any overstimulating of the receptors causes down regulation.
And I just found an assay with 8 adult males saying about desensitization.