In Ontario—because I live in Ontario—for genital surgery, yes, they need two physicians. If it's for breast removal, then they need only one physician, but they also have to be on hormones and they have to see some kind of psychologist who will give approval and say that yes, the person is experiencing dysphoria, and then put them on hormones.
However, for young children who have not started to go through puberty yet, they can go on hormone blockers, which gives them some time. It gives them time to really know who they are. It just puts their puberty on hold. That's the safest way to go for young children.