"The Perfectly Subtle Remaster..."

It's not a remaster. It's literally just an N64 rom running in a Switch emulator. That's been confirmed in pre-release coverage. The emulator may be applying some filters to make it look nicer, but Nintendo didn't do shit when it came to remastering the game

... That's not how filters work. The manner of getting a game to run is less important than the final results. If we throw out anything that emulates old code I have horrible news about a lot of remasters.

There's some Lua scripting hacks that are replacing some assets with redrawn or scaled art.