Cedille confirmed the composer listings a while ago at CocoeBiz. It's definitely Kamikura and Kaneda -- they've done many other works for the company.
Music compose & Supervise
Hitoshi Sakimoto
Sound Direction
Masaaki Kaneko
Music compose & Arrange
Masaharu Iwata
Mitsuhiro Kaneda
Kimihiro Abe
Noriyuki Kamikura
Manabu Namiki
Sound Management
Miki Ito
Pity a soundtrack release mainly depends on sales figure. Opoona really bombed at least in Japan (anyone have US sales figures?). Then again, so did Deltora Quest and that got a soundtrack release.
I can't entirely work out the designations of the 13 people at Basiscape. I assume newbies Yoshimi Kudo and Asuza Chiba are composer and mixing engineer respectively rather than both composers as we've previously thought, though subsequent game projects will probably confirm this. There also must have been a new manager (Akie Sato's replacement) and sound engineer join that I'm not aware of. I guess Miki Ito is officially designated a manager not a sound engineer and Masaaki Kaneko must be designated a sound engineer. I use sound engineer rather than 'SFX worker' as their roles have always encompassed a lot, from sound programming to voice editing to sound effects design. Anyway, Basiscape need a new website.