I don't think you can mix and match; I think the rockers are pretty integral to the seat design, though you can take the seat off the base. But the seats are also dimensioned differently. I've thought of trying to mount older seats in my 95, but of course that would change the upholstery style too. You'd have to change the mounting points on the floor for that, so it would take some pretty careful measuring and research.
I don't know why they changed the seats. The old ones were great.