Don't worry, I finished reading the manga years ago. I was talking carelessly because I assumed you too
I believe Momiji broke free from the Sohma "inner" clan and went on his own, pretty much like Kureno did. He never specifies where to, so likely he went far away to improve his skills and search for new people to love. Maybe traveling around the world? That would sound like him, but again, it's only my understanding.
And about Hatori, I wanted so much he could make up with Kana... but of course I knew it was impossible. Still, I would so much rather he fell in love again with a totally new unknown woman/character. I never like it when in a story they get together with people like "in the middle", to say it somehow.