Gender reassignment surgery is just a part of the process, not even the final step, there's lots to do before and after. You don't need to go over that specific part to identify or even come out as trans.
By the way, gender reassignment surgery usually refers to the genitalia, if the result is visible in a profile picture then it probably is just gender-affirming surgery, which is much quicker and easier to get done.
Some people might think trans people undergo a single procedure to get/remove breasts AND penis in one go, but no. Breasts usually are done first, and are the most important step to help strengthen one's own identity and self-esteem.
Consider the possibility that you are just a grindr hookup and not really friends so such sensitive subject is most likely to be omitted from the conversation.