I'm assuming they're referencing Doctor Octopus' voice sounding very similar to the Sonic voice in SEGASonic Cosmo Fighter. It does sound similar in pitch/tone, haha.
He means the voice. According to Wikipedia, Rodger Bumpass provided the Doctor Octopus voice... although there's no citation. I did a cursory poke on Google to see if Bumpass did any Sonic work, and allegedly he did have a role on Adventures of Sonic the Hedgehog. However, it's in a bubble of a "uncredited" listing and I can't find the episode. That being said, I'm kind of skeptical that Bumpass did do SegaWorld work... if he did we absolutely would've known by now. After all, if Michael Jackson hadn't helped with the attraction Michael Jackson's Scramble Training would've been buried into the tomb of magazines otherwise!
Yup that's the one. I've actually been on that ride a few times and heard that line delivery in person. It sounds very similar, obviously major difference in playback/recording tech being used, but it just sounded so much like him.