Well that's an unexpected twist, that's for sure. I guess this is how author is planning to resolve both Chika's subplot about his past (because of course it won't just go away, it was just ignored for now thanks to Chika's growth) and Momoya's family subplot (and probably touch on his daddy issues.) In any case, I have full faith in Chika's growth and that incoming drama will be handled with as much competence as previous ones were.
It was already hinted before that Momoya has complicated family issues so it wouldn't be surprising if Chika & co. didn't realize he was related to Uzuki.
And that moment between Chika and Satowa is what I live for, can't wait to see how will their relationship grow from here.