I thought I would add my screenshots to show how different the UVs used by the buttons are the new snapshots. As they show, it is no longer safe to use more than 4 pixels on the right side of the button wdigets textures, which will break several resource packs that use more than 4 pixels to create a custom edge shape for their buttons.
I'm getting the issue that I cannot launch old versions of the game such as Alpha and Infdev versions, as someone else also reported at https://bugs.mojang.com/browse/MCL-12691
Failed to download file, the file contents differ from what was expected.
Name: jinput-platform-2.0.5-natives-windows.jar
URL: https://libraries.minecraft.net/net/java/jinput/jinput-platform/2.0.5/jinput-platform-2.0.5-natives-windows.jar
Filename on disk: jinput-platform-2.0.5-natives-windows.jar
Path: C:\Users\LBLog\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput-platform\2.0.5\jinput-platform-2.0.5-natives-windows.jar
Exists: File
The fix looks really inelegant compared to how it was in previous versions (compare "test 3rd pre-release.png" and "test 1.19.3 game menu.png" that I attached to the issue). However, it does fix the issue, and I can't think of any actual resource packs off the top of my head that this would cause noticeable issues for, so I guess I can't really complain