I do think that people still care and I could see another project startdust-type resort plussing/triage being applied leading up to Disneyland Forward just as we had prior to Galaxy's Edge. Or what we saw in Toontown with the opening of MMRR.
Dinoland was a point of criticism that was finally addressed. I see DLR addressing 3 aspects within the next 15 years:
Backlot Area (Avatar Announced)
Tomorrowland
Pixar Pier/West Corner.
I know Marvel and Star Wars were both planned for Tomorrowland at different, which is why I believe that land has sat stagnant for so long. Hopefully they can now lock into what TL will be moving forward vs waiting to see if we're going to use that for something else soon.
I think a comparison is New Fantasyland in 1983. 28 years after Disneyland opened, they refreshed Fantasyland at a 2026-dollars cost of $150 million. As far as I know ride capacity didn't change, or at least much. I haven't watched any documentaries about the reasons for the project (are there?). But from the outside, it seems that theming and aesthetics, and some layout changes for traffic flow perhaps drove the project? Obviously it was a masterful improvement though, and has stood the test of time since (43 years since).
There are grumblings about PP now in the fan community. And I think it's easy to dismiss that. But fans aren't grumbling about Main Street, Fantasyland, Adventureland, New Orleans Square, Cars Land, Grizzly Peak. Not like the grumbling about Tomorrowland, Hollywood Backlot, and Pixar Pier. That is, fans don't just grumble at everything
in equal degrees. When fans grumble it's smoke, and where there's smoke there's fire. For a long while that fire may just be a small ember, hardly worth noticing. But over the years it can slowly grow, and catch on.
A few things will happen over the next 20 years I think that will lead to a change:
1. The land's hardware will get 20 years older. Rides age and while they can be kept alive quite long, maintenance costs increase, parts become scarce, and overhauls become necessary, and replacements get discussed. That goes for everything: wood, roofs, walkways, etc. Much of that infrastructure will be nearing 50 years old in 20 years.
2. Pixar, as a concept, is something we can hold in our head now. With just over 30 years of feature film history, there are fewer than 10 true hit franchises people associate with Pixar. The unsuccessful movies like Good Dino and Brave and Onward...can be ignored. The successes are few enough to hold as a curated collection that feels like it embodies a style and point of view. Twenty years and another mix of successes and failures to ignore and classic franchises milked for their third, fourth, or fifth movies, and I'm not sure Pixar will feel the same way. At some point when we can't hold it in our head, or even want to try, the theme will feel like what it is: mostly about the company's marcom agenda rather than what guests want, experientially.
3. DCA will be built out, potentially including Simba. So much of DCA's acreage will have been recently built that there will be nowhere to build new things, and showcase new IPs or ride systems, unless something existing is lost. They won't be tearing down Avatar/Zootopia, Avengers, Cars Land, or anything in Simba. Their eyes will wander across the park as they wonder "what needs to go?" to make room for whatever they think the park needs, and Pixar Pier will be the spot to reclaim.
But I think on a timeline side,
@Disney Irish is right to suggest 25 years.