The Legend of Zelda: Breath of the Wild appears to have gotten a speed boost following the VR update for both Breath of the Wild and Super Mario: Odyssey. The new speed bump shaves off at least five seconds off the loading screen, making it closer to the Wii U's load speed.
The speed bump was first recorded by speedrunner Alexis de Champris, who captured video from Breath of the Wild comparing the load times from before and after the VR update. In their two comparison videos, one of Link leaving a temple and the other of him entering one, you can see that the load speeds are much faster after the update.
Shrine entry is also faster with the update, which makes sense. pic.twitter.com/KUq9tYtqgB— Alexis de Champris (@Pikastroff) April 26, 2019
De Champris says that the footage was captured using Breath of the Wild running off of a cartridge, but that the speeds match the load times from the Wii U version of Breath of the Wild. At launch, it was noted that the Wii U version performed faster than the Switch version, despite the Switch being the newer console.
The speed bump seems to be from a secret feature as part of the Version 8.0.0 software update. The "Boost Mode" as it's being called, seems to overclock the Switch's CPU from 1GHz to 1.75GHz, but only in certain situations. This is presumably during load times, hence the faster speeds.
The speed bump so far has only been reported for Super Mario Odyssey and Breath of the Wild, but this could mean certain games could add updates that will allow them to take advantage of the new Boost Mode as well.