I thought that "Yub Nub" was fun because it worked for the small gathering of weathered warriors. It worked for the Ewoks culture and it seemed a lot more upbeat than the new music. When I first saw the ROTJ SE in theaters and the celebration music came on, it just seemed really depressing. I mean, the rebels just won a major victory, I would be partying! Not solemnly considering the effect on the rest of the galaxy.
I also think that the balance of music in that section of the movie was better originally. After all, the funeral pyre scene was sad and "Yub Nub" was happy. Now it is like going from sad to solemn.
The original music did have a piece that fit with that one ewok drumming on the stormtrooper helmets. The new music had a piece but it sounded a lot different and not as good in my opinion.
Rebel11_38