Source? I would like to see this interview myself.
Closest thing to that I could find is this:
NI/KH2U - Kingdom Hearts Ultimania
If KHII was never released, what would happen to the mysteries left in the first game?
I guess they'll just stay untold. (laugh) I have a severe opinion about that but I think a game that doesn't sell just shouldn't have a sequel. If many people want a sequel, I'll have to answer to that but if not, I have to bravely give up. Thank goodness we had a lot of fans saying they want a continuation so we were able to make it, but if KH was a game that nobody wants a sequel of, then it's not that bad for the unsolved mysteries to stay that way, anyway. Besides, even if KHII was not released now, the fans can still have fun with the underplots in the previous game and make their own speculations. In that way, although the game gets old, people can still continue being happy with it so I think it's possible to draw the curtain like how the previous game did.
A game sure needs elements where people can discuss and make speculation.
When we were kids, we always thought "there's not enough things to imagine from this" when reading manga, watching anime or playing games, and I thought that is strange. Whether it's game, anime or manga, there should be a place where you can speculate things, similar to a poker game, there are rules but there is always room for speculation. I have that feeling so I wanted to make a game that gives space for your imagination. That's why I don't like revealing everything and say "This is the answer." Just like when I was a kid, I want to make something that can allow people to let loose their imagination with.
Either way though, yeah, I was never for the idea of romance dragging BBS down, especially Ven and Aqua. There's nothing that really solidifies a romantic connection between her or Ven atm, same with Terra. We'll probably get lots of butt-buddy action between Terra and Ven though because it helps the games sell :v