Well, you had Walter Lanz at United Artists, Bob Clampett and others. Warner had no trouble jumping into the cartoon business in the early thirties. Talking movies were an emerging art form, so the absence of the Disney characters might have less industrial impact than many would think. You had Hanna and Barbera from the fifties forward into the television era. The biggest difference would be the theme parks. But Disneyland did not open until 1955, so the differences would happen somewhat later. Disney also enlarged the mechanical rides to accommodate whole families, not just kids. These are the places where the changes would be greatest.