I would say pack-in title would refer to a bundle that was active for a substantial time, like Wii Sports on the Wii. The Metroid Prime bundle was just active during the release of the game, 3 years after it launched.
You are trying to split hairs on synonymous terminology in an effort to correct me when my original statement was already correct, and doubling down. Why?
Call it a bundle if you like, but the game itself was a packed-in the box and sold as an item with the GameCube, i.e. a pack-in.
Call it a bundle if you like, but the game itself was a packed-in the box and sold as an item with the GameCube, i.e. a pack-in.