They were sounds played on the Mediastation, its not like the sounds produced and played themselves. We don't know yet if the backing was a custom style the user created or if they were sequences done on the MS. Either way the sounds, drums, and files were played on the Mediastation.

Would you question the Tyros 3 if I sequenced music on it and used some custom samples or custom voices I created myself on the Tyros 3? I'll bet you wouldn't. The advantage the Mediastation has is the ability to utilize so many different sound sources that most arrangers lack. Why knock that technology rather than embrace it?