Actually if Oda did not retconnect anything it would make sense if Sora is from King's race.
Judge did not tell anything about Diable Jambe or genetic modification so it would be strange if he really used king's race dna in Sanji's body. At least he could have said something about Diable Jambe.
So it would explain what Sora's drug did. She let Sanji kept emotions intact and protected Sanji from Judge modifications that maybe had the possibility to overwrite King's tribe genetics (Sora's genes).
So Sanji thanks to the drug only took the genetics from the mother and nothing from the modified lineage factor from Judge.
Judge did not tell anything about Diable Jambe or genetic modification so it would be strange if he really used king's race dna in Sanji's body. At least he could have said something about Diable Jambe.
So it would explain what Sora's drug did. She let Sanji kept emotions intact and protected Sanji from Judge modifications that maybe had the possibility to overwrite King's tribe genetics (Sora's genes).
So Sanji thanks to the drug only took the genetics from the mother and nothing from the modified lineage factor from Judge.
This would also mean that Sanji is the "real" son of Sora because he’s not a modified human and has her genes