There’s no “speeding up” or “slowing down” of film, it’s shot how it is. You can run the camera slow or fast and get the result that when played at 24fps you get fast or slow motion. Toy Story was rendered frame-by-frame for standard 24fps projection.
Agreed, however, when you compare both the Laserdisc and the DVD, if you overlay them both over each other in a side by side comparison (something I did in iMovie as a test), the laserdisc goes out of sync with the DVD very quickly. So yes you are right, the film was not “slowed down” or “sped up”. The film just gained and lost some frames in some shots on the film out. So yeah, it was rendered frame by frame for standard 24fps projection, its just that when Pixar were processing the film for celluloid, the Avid Video Composer caused the movie to gain and lose a frame in all of the shots.