Considering Nintendo prototyped Wii Motion controls on Gamecube to start with...
https://arstechnica.com/gaming/2018/10/japanese-auction-reveals-nintendos-first-wii-remote-for-the-gamecube/
And considering the Wii basicaly had the same internals as the Gamecube anyway... With some enhancements...
https://www.copetti.org/writings/consoles/wii/
And considering some Gamecube games have been "broken down" and discovered to have been tested with "motion controls" on the Gamecube like the prototype of Metroid Prime 3: Corruption included debug options that featured motion control functionality
The issue isn't so much a question of "Can the Wii release a generation earlier" - It literally could have from a hardware perspective.
The issue was software, it just wasn't ready.
Nintendo could have release motion controls as a literal accessory of the Gamecube.
--::{PC Gaming Master Race}::--
