Mitsuki seems to respect Oro. He even went far as to say Oro was cooler/better than Naruto & Sasuke. And he seems to want Bolt and Sarada to respect Oro when talking about parents. And he smiles when he reveals his parentage.
So they may have a distant relationship, being they don't live together. But I like to think Oro cares about him. Enough to send him to the village he grew up in, where Kabuto is also working, as opposed to experimenting on him.
Maybe this is Orochimaru's new thing. Like Xanatos from Gargoyles, who feared mortality. He didn't want to get old, or die. it's the one thing that made him uneasy. Then Hudson tells him true immortality isn't always about living longer, but what you make of your time, and the legacy you leave behind. Xanatos later had a son. Children, and later descendants can be a good legacy - unless they turn out to be psycho. But Mitsuki seems like a stable and trustworthy fellow. And he has much respect for his father. So, he may be Oro's new legacy. He has a son, that's a part of him to live on, and something to love, since his parents.
But Lord knows. Too bad Kishi didn't give more on that. But I guess he wanted to leave some things to fans' imagination.
