It's not his chest that is bothersome, it's where his character is ending up.
If the same character who had no qualms destroying 50+ newborns and sacrificing children is now a good guy and loving parent... it'll just make me feel a certain way.
Kabuto is another one of my faves and I felt uncomfortable with him being in charge of an orphanage even when knowing it was 100% safe (because of Izanami treatment).
I don't know, some characters shouldn't have 180 degree transformations just for the sake of a narrative to continue, it should come more naturally than this and at times lines can be crossed to the point you should not portray a character in the opposing way; there have been no hints of Orochimaru having the capability to be a loving parent, only the opposite. So why now? Hopefully there's a twist to this and he considers Mitsuki more of a tool.