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I'd say let's get animations done for everyone that doesn't have one before worrying about updating old ones. If we can get any animations at all, that is. It's been more than 100 days since the last update.
on a semi-related note, i found some good gen 9 menu sprites on twitter. I don't know if the artist would want them used on showdown but i'll link their deviantart here just in case.
https://www.deviantart.com/ezerart
looks great so far! glad that you did the battle animations instead of just ripping the idles from the menu like some people
and yeah i'd love to see the rest of gen 8 finished, can't wait to see more