The tourism industry in Hong Kong benefits from the influx of mainland Chinese tourists that come to Hong Kong for vacation. Disneyland always attracts tourists from all around the world to visit their parks. But you can typically see the Disneyland Park in a day or two and then tourists explore other attractions in the area.
I lived in Germany for three years and lived about six hours away from Euro Disney located in Paris. My daughter, at the time was 9, wanted to visit Euro Disney so we planned a trip to see the park. But because we had to travel so far to see the park we decided to stay the weekend in Paris and see the rest of the city as well. Not that Paris needs help attracting tourists, but Disney does help attract families with younger kids. These families must include kid centric activities during vacations and Disney offers families a vacation that kids will remember for their entire life. Therefore cities that have a Disney Park will benefit from an influx of families with children from all around the world who will stay in the city longer than just the time it takes to see the Disney Park.