I mean this sincerely -- I'm glad this board includes people such as yourself with unbounded optimism, that help lighten the atmosphere when things get too gloomy. That said, your interpretation of events doesn't appear to match reality.
20,000 Leagues was closed to lower operations costs, pure and simple. You talk about when the lagoon was drained and filled, but that was actually years after the ride closed. Rumors existed about Bald Mountain, but I never heard they got anywhere close to greenlighting it. It's not like, say, Mr. Toad, which was closed in order to put Winnie-the-Pooh in the same place (and which was announced at the same time). 20,000 Leagues was closed, the money to operate it was pocketed, and then many years later, they decided to make use of the same area for a set of new attractions.
In the same way, any demo of WoL, unless it is accompanied by an announcement of development of the same space, would simply be a demo, and wouldn't make any future attraction more likely.