Bruce didn’t show up until September 2000, i.e. two years after recording began, and even then his role was limited to mixing previously recorded material. He wasn’t actively involved in engineering until March 2001, two-and-a-half months before the album was finished. He also wasn’t involved in figuring out the album’s running order for the first time in years (if you’re excluding Blood on the Dance Floor).
Sure, Bruce was involved with Invincible—at, like, a fourth of the role he played in albums prior.