Yes, it seems to be the case. At least added as MP3 download.
More details about the band members of the Primals and piano arrangements have been added a few days ago to the website:
http://www.square-enix.co.jp/music/sem/page/ff14/atou/
Nobuko Toda lending a hand for the piano part.
Regarding the credits, Keisuke Kubota and KID are included as "tour supporters" so I guess that means they are not actually featured on the album.