Does anyone know if I get top surgery before I start T If my chest will change for the worse?  Idk when I will start T but my chest makes me very insecure and I want it gone.

Two years post op here with no T and boobs haven't grown back. It is more and more common for guys to get top surgery first. There is no order that you have to follow. You don't really have anything to worry about unless you got really overweight and then it would just be fat up there and not boob like a cisguy.

I haven't heard of breasts growing back if you have the surgery before T. It's just recommended to have it done a year or two after being on T because the fat on your chest would have redistributed; giving you slightly better results.

The breasts cannot literally grow back anyway, since they remove the very organ (mammary glands) that grows into breast tissue. What can happen is the development of man boobs if you are overweight, but this is different from the removal of breast tissue. Also, breast tissue only grows up to a point which is why your breasts don't grow indefinitely once puberty ends.

You can do top surgery first. More and more surgeons are becoming open to the idea, or have been open to it for a while. They won't grow back, it won't look bad.

I had top surgery before I started T.  Was not sure at that time if I would ever want to take testosterone, but knew that I needed the surgery.  My chest is fine. Great, actually, and now that I have been on T for many years, my pecs have filled out adequately (with lots of push ups). 

I just want to say, this is so comforting to hear. I'm actually non-binary rather than ftm, but I think I will probably want top surgery. However, I currently have no interest in T, and was scared I couldn't have top surgery without it. Thanks for clearing that up!