It's true that he's likely going to continue working with SE/FF in some capacity as a freelancer, but it's worth generally bearing in mind that Kamikokuryo's role on most of the big projects he's been on has been to head up a larger art team and try to provide a guiding direction that keeps the game as a cohesive whole. This often involved major art coming from other sources (Hasegawa, Nomura, Naora, Minaba, Yoshida etc) plus a bunch of smaller, junior artists working under them. He became the go-to guy for unifying a game's direction in that sense.
This sort of job is unlikely to be one that can be done effectively from outside SE, especially with the sheer amount of art needed for a major game like a full-scale FF, so I think it's fairly unlikely we'll see him take on that kind of job again. I'm sure we'll see him contribute character designs and concept designs to games in the same way Yoshida has since leaving SE, though... but that's very different to his fingerprints being all over the game's visual identity from top to bottom.
Given the size of art teams, I think it's pretty hard for an artist to be effective in the same way as an outsider compared to composers, who work in relative isolation anyway.
There are plenty of great people left who can do that job anyway... it'll just be different. In that sense I'll miss him being in-house.