I went to SCC this past Sept, for the first time - actually my first time ever out of the house en femme. I met quite a few MtF, FtM people there at all stages of transition, including a few noobs like me. Yes, there are a number of CDs, Drag King/Queens, and what not, but it is a very diverse cross-section of the community.
There were quite a few doctors and therapists in attendance, not all giving lectures. I would say that it would be very worth his time going. I heard that there were more than 900 trans people who attended last year. What kind of doctor is he? That may help to determine if he would benefit from attending.
Deanna