Uh, no. If the haraSSSSee has a non-haraSSSSment BP either arriving into or departing from the airport where the haraSSSSee is already airside, then the haraSSSSee may be "on-ed" (boarded) without receiving haraSSSSment.
This may be true ... we're not privy to all the rules airlines operate under!
People are rebooked all the time, and come back through the checkpoint with SSSS boarding passes as a result, and they're not exempted simply because they were rebooked. (I generally advise them to try to get the airline to give them a non-SSSS boarding pass in the future.)
I've also been called to do gate screenings on people whose SSSS boarding passes were issued airside ... they clearly didn't come through the checkpoint (no initials on the passes). Didn't inquire as to the circumstances ... just screened them and sent them on their way.