There's no thread for this, so I'll just share this here.
I found some tidbits about Phoenix Studio's Rayman 4.
Gaël Chaize was an art director & 3D modeling artist at Phoenix Studio. He shows a render of a 3D environment
on his website with the caption "Rayman prototype":
I also found the person who presumably animated the "Rayman Sings Sex Bomb" video and the Rayman 4 teaser where he gets called by Ubisoft on the beach: Damien Pougheon. He linked 2 Rayman videos on his website, though the videos themselves are long gone (maybe someone should ask him if he still has them?). I think the "Disco party" video might be "Rayman Sings Sex Bomb", but from the thumbnail the other one looks like it's rendered in-engine?
Une animation test marrante pour prendre en main le personnage ( Rayman pour les non-initiés), faite l'année dernière durant la preprod du j...
dams-animation.blogspot.com
Après la disco party, voici quelques autres tests d'animation... After the disco party, here's a bunch of test animations... (Cliquez sur l'...
dams-animation.blogspot.com
He posted this in April 2006, when the game was already cancelled, and he explains he made these during preproduction the year before.
Lastly, evidence of two cancelled Rayman games. Pascal Cammisotto was a game designer at Phoenix Studio.
On his resume:
2006 : Lead Game Designer sur un jeu "Rayman" sur PsP (annulé). (Ubisoft)
2006 : Game Designer sur un jeu "Rayman" sur Xbox360/PS3/PC (annulé). (Ubisoft)
It seems that the Phoenix Studio game was for Xbox 360/PS3/PC, and either they also had a separate project for a PSP version, or he was transferred to a PSP game afterwards -- which would explain early listings of a PSP version of RRR floating around the internet.