The way Unite handled SWSH was weird because it came out like 6 months after it came out
We often forget that Eldegoss was one of the first mons they revealed for SWSH after the starters; they seemingly kinda believed in it?
I don't think it's that popular in JP either tbh, in general the Unite roster during Gen 8 and now Gen 9 has had an air of "Well we gotta include mons from the latest gen". Gen 8 in particular being rough because there aren't that many hitters. Out of any region, they got the most creative with picks for Gen 8, including Greedent for Halloween.
I don't intend to suggest that Unite is fully 100% "well this is popular let's put it in", especially considering sometimes they go out of their way for certain roles (I don't think Blissey/Comfey are particularly popular, but most Pokemon don't fit for a support mon!), sometimes it's to plagiarize a LoL character, and sometimes it's just cuz region quota.
But I think it can give an insight into where TPC is thinking sometimes.
For Gen 9 they've been much more popular picks than they did when SWSH was fresh: Meowscarada, Miraidon, Ceruledge and upcoming Armarogue in that order has been their picks so far.
also this should be up to date:
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