But at some point personalities and people themselves fade into history, and it becomes a historical figure (such as Lincoln).

Namely how many people alive actually knew the person.

He clearly had no problem with representing the company and actively promoting Disney theme parks, movies and products with his image. Even while he was alive Disney Corp sold high-end memorabilia like large framed pictures of Walt working at his drawing board and including his distinctive signature. So he not only promoted products but turned himself into a revenue generating product. In some sense, he made himself a mascot for his company as much as Mickey Mouse and this was clearly by design. To me that's different than a CEO who mostly limited his public exposure to the usual earnings calls and shareholder's meetings.

The video is segmented into chapters--if you're not interested in the whole thing, the section about the Lincoln animatronic is chapter 4, about an hour into the video.