>>54945683Perrin has a Hisuian Growlithe though.
Ursarings, Stantlers etc exist in present time so it's not that the family as a species went extinct, they just lost their evolving methods. Bloodmoon Ursaluna is probably not 200 years old; there's a population somewhere.
And modern Sinnoh has tons of unaccessable areas inbetween, small populations of Hisuian regionals may be around in some fashion. They may have migrated to other regions as well.