He's commented that a balefired individual can be spun back into the pattern. However, this is not the same as what the Dark One does, grabbing a soul and placing it into a new adult body with their memories intact. When someone is reborn through the pattern, they truly are born again and spun anew with a new life that will build new memories. Balefire prevents the DO from using his method of soul migration, thus eliminating the Forsaken as threats for the foreseeable future... That's all TGS was explaining. From the perspective of Rand and the characters, balefire is "permanent" threat elimination. It's extraordinarily unlikely a balefired individual will be spun again for at least another age or two if not longer.