Usually the reasoning for an actor to abandon a successful character is out of fear of being typecast. Since a ride is a mere collection of clips with focus on the actual "ride" aspect as opposed to the acting and players involved, it's possible to film some small segments without ruining your Hollywood credit. I mean, are rides even part of an actors' filmography? Either way, if they pay him enough, I'm sure he'd take it as something this small isn't really damaging to your career.
On the other hand, his role in the ride could be comprised solely of stock footage and CGI. In which case, he still appears, but he didn't have to do anything.