A bit of a rant incoming. I apologize in advance for rambling.
This decision still just baffles me, even a day later. I at least understood the reasons for Mission Breakout; Twilight Zone is a non-Disney property that doesn't bring in the merch $$$ like the home-owned Guardians. But the current attractions in Paradise Pier are already Disney-themed. The land was remodeled just five years ago, and is now a very cute and nostalgic mixture of old-school Disney and old-school seaside theme parks. I feel like throwing in Pixar kind of ruins that, considering Pixar IPs are distinctly modern and don't mesh with the classic boardwalk tone at all. I know Toy Story Midway Mania was already there, but that's a single dark ride specifically made to match the theme, not the basis for an entire land. Meanwhile changing Silly Symphony Swings to something like Toy Story Swings or making Mickey's Fun Wheel into "Pixar Fun Wheel" just seems so forced and inorganic. Was Pixar merch not selling enough at the rest of the resort? Do we really need MORE Pixar content at DCA, which already is FULL of Pixar?
The biggest thing I take from this is that the California theme is truly dead. While it was never strong, I think they found a nice balance after the 2012 redo. Not everything was perfect (such as Radiator Springs technically being in Arizona), but every land had a distinct Californian tone; Grizzly Peak is obviously Yellowstone-inspired, Cars Land brings to mind iconic desert towns and canyons that exist throughout California, Paradise Pier is based off the Californian seaside boardwalks of old, Hollywood and Buena Vista Street are obvious. The only true outlier was Bug's Land. But with Soarin' Over California gone, the Hollywood Tower Hotel gone, Paradise Pier becoming Pixar Pier, and (seemingly) Marvel Land taking parts of Hollywood Land... if the park wasn't due for a rename in the past, it definitely is now.