I disagree. If anything, it increases aromatase expression, which an AI will still take care of.
The only way that an AI wouldn't work is if HCG converts directly to estrogen through some other means that the aromatase enzyme (which it cannot, since a peptide chain has a completely different structure than a sex hormone), or if it caused your adrenal glands to pump out an insane amount of estrogen. This is highly unlikely, since adrenal E2 production only accounts for maybe 2% of natural E2 levels in men.
I haven't worried about this much lately, but I'm fairly certain the estrogenic effects of HCG are mainly due to it increasing Leydig cell activity in the testes, which is also where most E2 conversion takes place E2 is not produced by the testes, as you say, but by aromatase enzymes within the leydig cells of the testes).
http://en.wikipedia.org/wiki/Estradi...e_reproduction