I've already explained last Month that Ancient Kingdom has nothing to do with D.
D. are basically people who were modified by Scientist "Willie Gallon" to Host Powers of Story's Final Secondary Villain
Basically, similar to how Caesar created Smile Army for Kaidou (Army of Beasts for Man known as King of Beasts)
And He also modified Children who gained similar Qualities to Big Mom (Second Monster of Wano Saga)
Willie Gallon created Sea Kings Army for Story's Main Villain (Army of Sea Kings for Villain known as Sea God)
And He also modified certain People to gain similar Qualities to Final Secondary Villain (Sea Devil, similar to what Oars was for Moria)
Those People became known as D. Family
And that's why Nefertari Lili disappeared, it's no different than Disappearance of Mocha for example, Willie Gallon took her.
And just like Momo ended up with Punk Hazard Kids by Mistake, there is a Man who ended up gaining D. Name but wasn't modified like them
Who is Momo? Leader of Rebellion against Kaidou & One who replaced him (Both have same DF)
So Outsider D. is none other than Leader of All Rebels & Man who is meant to replace Sea God (Both have same Power which is Storms)
That's Monkey D. Dragon
So either Dragon is not from "Monkey D." Family or entire Monkey Family isn't from D. at all