I don't really have too much of a problem with showing the celebrations on other planets, I always saw it as a montage of events that happen after the fall of the Empire, and not neccesarily at the same time as the Ewok celebration, although there do seem some inconsistencies for instance why are they celebrating on Tatooine? when it was always considered to be too remote a planet for the Empire to be interested, and was under Hutt rule?
and I always assumed that Cloud city would have been abandoned after Lando gave the order to evacuate at the end of Empire.
and lastly, considering theres no reference at all to Naboo in the original trilogy even though it seemed to play such a crucial role in the prequals, George messed up the perfect opportunity to wipe out the planet in catastrophic fashion, considering how the planet seems to have remained completely unchanged in over 30 years from the first film.