I had SRS with brassard/belanger and did no hair removal before and have no hair in my vagina now. My gyno confirmed this, and so has my wife.
As for laser before surg with brassard, he does not want you to do that because he scrapes the follicles during the surgery and follicles that have been laser treated, as we all know, are not always killed off, but gone for a while, then grow back. If they are gone during the surgery, then he cannot see them to scrape them, and they will grow back after the surg and you will have hairs in your vagina. My paperwork for surgery explicitly stated this, so I would recommend contacting his office before doing laser or electrolysis as preparation for surgery with them.