When you disabled animation effects on your Windows, and then open Minecraft, the Mojang Studios logo will no longer fades out and will instantly disappear instead, this seems to only happens in Windows 11, as in Windows 10 the Mojang Studios logo fade out as expected even if the animation effects is disabled.
Steps to reproduce:
Open Windows Settings, then go to Accessibility > Visual Effects, and then disabled "Animation effects"
Or if you prefer using Control Panel: open Control Panel, then go to Ease of Access > Ease of Access Center > Make the computer easier to see, and then enabled "Turn off all unnecessary animations (when possible)"
Open Minecraft
Expected results:
Mojang Studios logo fades out as expected.
Observed results:
Mojang Studios logo does not fades out, instead it will instantly disappear.
Can confirm