Lesinutah
Les,
Yes, it does. The G3/G4 hose can be used on the G5 and later machines, but the gasket on the hose connector has to be removed first.
But, as the same article you mention says... to use the G5/Avalir II hose on the G3 and G4, let alone a G5/Avalir II nozzle (so the oblique brush roll can be used) or Carpet Shampoo System, the fan case will need to be changed to the type used on the G5/Avalir II.
Personally, I would never do that for the sake of resale value.
~Ben