Oh yeah, there were never female Custodes mentioned, which is why it was such a debate. My best guess is that Gee Dubs overlooked it when they changed Space Marines to male-only genetically modified supersoldiers after the Rogue Trader days, and when they realized their mistake, decided to keep it ambiguous in the Custodes’ case they wanted to change it later.
Oh yeah, there were never female Custodes mentioned, which is why it was such a debate. My best guess is that Gee Dubs overlooked it when they changed Space Marines to male-only genetically modified supersoldiers after the Rogue Trader days, and when they realized their mistake, decided to keep it ambiguous in the Custodes’ case they wanted to change it later.