Board Thread:Warhammer 40k General Discussion/@comment-20282318-20140210075721/@comment-81.157.232.135-20180418160023

I would say yes and no aswell, as it says in the wiki 40k, "In specific terms, the recruit must be about 10-16 Terran standard years of age, although the process has been documented to still work in recruits as old as 20 as long as they have not yet reached their full adult growth"

so there is a small chance or window of opperchunity, if the individal has married early at 18-20 and had kids or just had kids, or sperm banking (if they still have those in the 41st millenia). Plus as you said they would "have very little interaction with them due to long campaigns: if you're dad's a Salamander then you might see him once as a baby before he goes on campaign ... and if you're luck you'll see him again as a 90 year old man when he returns in between campaigns ... then you're great-great grandson will see try to pass initiation and if he passes than he MIGHT meet up with your father again". and the enemy will use this against you.

That is way i had to research this before making my lore for my blood raven terminator veteren sergeant who is from krieg. You can can see this on deviant art https://general-skull.deviantart.com/art/RAVEN-OF-KRIEG-730387016