Bad analogy since timbre has been part of the compositional process for decades now.

This is exactly what I'm talking about. In Western music timbre is akin to fonts. You have a composition for piano, you play it, record it in MIDI, and reskin it with some other timbre in studio. This is an extremely Western way of looking at music. There are countless cultures where timbre is the "main" part of the music where the harmony and/or rhythm would be like fonts/reskins and timbre is the main juice composers and improvisers try to squeeze out. This type of distorted view on music is rooted in 18th/19th century beliefs of non-Western art being "primitive" art even though every single culture that's known to humanity have a unique musical tradition. This is an extremely anti-humanistic look at music.