Yeah, it does seem to be hinting that the MC's father will end up being the first traveler dude and somehow we're the only male progeny - perhaps he decided he wanted to finally have a son for some reason, or Duvessa and/or some other forces conspired to ensure the MC would be a male rather than a female, despite being born from him - which would also go some way to explain why there was even any question as to whether the MC could potentially become a traveler in the first place, considering the family all knew that only women could travel, and MC being born a male, they must have had reason to assume there was a chance that he could be the exception. Also bonus incest points for making him Kylie's uncle and Astra's half-brother that way (plus all the extra progeny incest that could happen).. But I definitely think that if that were to be the case, it would both be something that could still easily fit into the standard incest story with Gemma as your mother and Derek/Derin as step-parent, and the other siblings all either half or full siblings depending on whether they were fathered by the same father or not (assuming Derek/Derin preferred to stay as Derek and "watch" rather than be the mother themself), and would be really awkward to have it first tell the MC that he's not related to the rest of the family, only to turn around and then say "actually he is, but in a different way, I guess".