They did transplant the scrotum. I wonder if they included some cosmetic testicles just to make the patient look more "fully equipped".
I say that as someone who was quite vain about my looks when I was young, but chronic health problems have drastically changed my priorities.
That's not intended as dismissive. I just kind of feel like it's a detail likely to be a low priority at this stage, what with it being groundbreaking surgery to begin with, etc.
This article indicates he's also missing his lower legs:
https://www.npr.org/sections/health-shots/2018/04/23/6050544...
No indication if they made the scrotum look like there are testes.
Google tells me that "testicular prostheses have been used for 50 years to replace missing or removed testes"...
I would speculate that they would be a relatively simple addition to the surgery itself, but at the very least it would be very simple to do as an additional operation once the transplant stabilized.
https://www.parsemus.org/projects/calcium-chloride/
Two intratesticular or intraepididymal shots are far cheaper and so much less invasive than two surgeries.