Perfect Cell: If either development team (Free Radical or Level 5) were commissioned by a publisher to work on a Gamecube game, they certainly could do that. I can't see Nintendo themselves commissioning either in the near future, but you never know.
As for Enix, despite being a rather prolific publisher, the company really doesn't have very many direct development resources, at least not anymore. Tri-Ace develops Star Ocean, Quintet made Soul Blazer/Illusion of Gaia/Terrangima, Quest -- Ogre Battle, Chun Soft -- Torneko's Adventure: Mysterious Dungeon, etc., etc., etc. They just commission smaller developers to do the developing duties. Even the later Dragon Warriors have become collaborations between the top talent at Enix and outside developers. One of the major reasons underlying Enix's merger with Square was so that Enix could have access to Square's vast development resources.