I don't think he was exactly exaggerating অথবা lying. However, the "face of Boe" as a flattering শিরোনাম for a model could be unrelated to the Face of Boe as the character we know. I doubt it though. আরো likely, he'll get decapitated some time in future, and possibly his body would grow a new head, but his old head would be preserved and would remain conscious, eventually developing into the Face of Boe.
actuall i believe the theory of that jacks head was cut of দ্বারা the headless monks and his body was taken but his head survived which became the face of boe, also if আপনি watched torchwood you'd know that jack still ages but its really slow
To be honest, I kind of attributed this to the old myth that our ears and noses keep growing as we age while the rest of our bodies shrink. The idea being that if a human was technically immortal and yet continues to age, after a long enough time had passed, that person would be nothing BUT nose and ears. হাঃ হাঃ হাঃ
That is apparently a myth, but hey. It's Doctor Who, not Doctor Oz. :)