Infostalk has already pointed out that an AI will not lower estrogen levels to zero. I think it's more like 75-80%, but could be wrong.
AROMATASE is an enzyme found in the liver, it's responsible for the conversion of the androgens ANDROSTENEDIONE and TESTOSTERONE into the estrogens ESTRONE and ESTRADIOL. By inhibiting aromatase the body produces less estrogen and maintains a higher testosterone state.
So the answer to your Q is false.