You don't think of driveshaft "weight", but it's there. Having a center support to help hold it up makes life easier on the rear tail shaft bushing (relates to rear tail seal life and leaks). A two-piece shaft has different vibration harmonics, too, than a single-piece unit.
IF there are any "water shields" on each side of the bearing, keep and reinstall them--period! It might be a "sealed bearing", but NOT sealed that well against moisture or dust. The deflectors are there for a purpose, too! We discovered that when a tech changed the carrier bearing in our '69 Chevy pickup, said "These aren't needed. It's a sealed bearing." And chunked them. One year later, the bearing was full of grit and needed replacement, plus a new set of deflectors, which it got.
CBODY67