Most of the shifting is done at the shifters, so I'd say it could work.
However rear derailleurs might differ slightly in their actuation ratio i.e. the amount of cable pulled at the derailleur vs at the shifter.
Apparently in 2001 the actuation ratio changed, so you're better off with an older derailleur (8sp of course, but surely 7 or 9sp as well). If the difference is large (with modern ones) then the shifting might be a bit sluggish, but I don't know in practise.
Check ebay, you can surely find a used 8sp derailleur for less than a 9/10sp modern one.