Yeah, family ties due to legacy makes sense now, and I get why it's coming into the series now. It's just a bit of whiplash for me that I'm still adjusting too aha.I think the use of family is specifically in the context of Keyblade Society, which is the center of all these prequel games. Technically this was established from BBS' description of Eraqus' bloodline.
Of course by the time of BBS, the society has completely dwindled to random masters training kids they found alone, and then by KH1 there is no keyblade society, and the weapon can only be taken up by children who know nothing of all of this. And so family is not very important in the present day.
Like I said, one of the unfunniest jokes is Sora's mothers dinner and that's been around since 2002. People have wondered about family since then. We've heard of Sora's father, Kairi was raised by the mayor etc. but the way the KH games worked, we were told that family wasn't important (and even over a decade ago, this forum would "flame" people for asking about parents and linage, saying it isn't important.) I'm just getting a bit of narrative whiplash, that's all. Now when Quadratum has a dating simulator mini-game and Sora has to meet the parents, I'll be kickstarting this conversation up all over again .
It was interesting to see Eraqus starting his Keyblade Mastery journey by having him feel like it's a requirement due to his heritage, and then come into his own and finding what he wants out of it. I enjoyed that aspect and I'm keen to see how bloodlines affected Scala during Missing Link's timeline.