I'd say that's a very cynical way of looking at what's happening here.
But if they just wanted to build a theme park expansion, why not just ask to rezone the area for theme park space?
The less cynical take here, is that what they want to build is a "New Experience" that doesn't really fit the molds outlined in the 1996 agreement. It's not really a theme park and it's not really a dining/retail district. Something of a hybrid between them. Since that concept is hard to understand, especially to the general public, they are rolling it out as a mixed use space that COULD be used for those individual pieces.
With the splitting up of WDI, there is a little more context to this. WDI is going to start branching out into fields that are not typically theme park centric, and for an organization structured around theme park design, that change means a lot to job classifications and direction of work and what projects get grouped together. If you've been following Disney/WDI news for awhile... almost nothing about this "change" in direction will be a surprise to you.
At the highest level what this may mean, and what I am putting my money on, is more of that "direct-to-consumer" attraction experience that they floated around with in the 1990s with DisneyQuest. Moving into the field of having VR attractions like The Void or "flex" attractions located in a retail/dining environment that would offer a low-price, pay-per-play, option against the pricier theme parks.
And with the changes to the AP program, something like this would be a perfect alternative to bringing back significant discounting to the parks. APs may not be ready to spend $100+ dollars a day on a Disney Park experience, but maybe a $10-$20 ride ticket for a specific attraction or an expansion land would be a good alternative?
I don't know... it all seems so clear to me. This is also why they denote the space formally for the third park as a new kind of Disney entertainment... not really a park, not really a Downtown Disney.
Also there is potential growth in being able to roll out these micro-park experience to other cities locales, if it works.