Judging from the surge in popularity from just the anime's PV, I think it's going to pull in a lot of new fans. Not only does it bring fresh Ainu culture to the table, it's comedic yet has that bloody edge that most trending anime seem to have these days. It might not necessarily be huge, but it's going to be big, at the very least.
Fandom drama wise, I can already see some parts of the show being nitpicked and pointed out as problematic (eg pedophilia, transmisogyny, cultural appropriation) but I hope these'll be stamped out as soon as they happen.
On that note, which character do you think will be the most popular? From the Japanese side of the fandom I'm seeing a lot of Ogata enthusiasts but the Western side doesn't seem to like him very much.