Cutting off a diseased part of the body is medicine. And the goal of cosmetic surgery is to improve one's appearance. SRS is neither of those things. Cutting off healthy, normal bits is mutilation.

probably will add stigma to detransition

I think hurting their feeling with a blunt choice of words is the least of post-op detrans concerns. I don't know if you read r/detrans, but these people know they fucked up bad. I don't think sugar-coating it is going to do any good.