I realise that this is a sideways step, but, some say that songwriter, Charles K Harris changed the landscape of American popular song, and that was his legacy. Yes, and what about what happens afterwards? ... The title to your indepth observations on this topic speaks a lot Hans.

After the ball is over
After the break of morn
After the athletes'(dancers') leaving
After the stars are gone
Many a heart is aching
If you could read them all
Many the hopes that have vanished
After the ball

There is another aspect of this big events that is seldom mentioned.
That is the impact it has on other tourism ventures. A big example was the Olympic Games in Sydney. It brought a lot of International visitors to Australia and after wards some of these people visited well known tourist spots like the Great Barrier Reef or the Red Centre. But these people did not go to less well known tourism districts. Nor did Australian tourists visit such areas. They went to Sydney, or they stayed home to watch the events on TV. Even if they were driving through a tourism district after their visit to Sydney they had overspent and were not inclined to spend extra money.
So it is with any big event, even an annual car race on the Queensland Gold Coast could pull weekend visitors to that area for one weekend, but other southeastern Queensland tourism districts would get less visitors at that time.
My point is that large tourism events are only of value to that location for their duration, but have an overall negative effect on other locations for an extended period.
It was also reported of the Sydney Olympics that restaurants etc. on the other side of Sydney lost patronage and therefore income during this major event.