How is this so? If you are eating a surplus of calories, you'll gain weight no matter what. I've been on TRT for about 5-6mos now.. I've noticed a slight boost in metabolism, some muscle gain, but any fat lost has been the result of eating less. I don't know exact numbers but the scale has hardly gone down (maybe 4-5 lbs) but I've recomped a little with TRT.
Higher body fat = more aromatase activity = more estrogen. This can make it harder to lose body fat and actually gain it instead of losing it.