I don't think he's involved. But they probably ask him for permission before using new moves. And since this movie was released before luffy showed his second gear, they chose to make it come all random. But as far as I remember, the mangaka has almost nothing to do with the anime script, probably less with the movies.
Let it be known far and wide
I cheer for Saint-Etienne from the bottom of my heart
While I agree Movie 7 was pretty good, when you compare it to the movies before 6, and the TV specials, it feels subpar to me...
It had some good moments... Robin, Bouncy Nami (kinda a good/bad thing), Luffy stuck in a wall (twice), GEAR SECOND!!!, and other general a$$-kicking...
But unlike the the other movies and tv specials, it has 6's cheesy computer graphics, not as likable character designs, and... pretty uninteresting plot, I'm afraid to say. And WHERE was the funny? Not that there weren't funny moments, but One Piece normally has me dying of laughter, with Action and Story Bits added for flavor.
Yeah, I'd definitely put the TV specials before 6 and 7, but it's still all One Piece goodness.