>>49273173I don't think it's Hisuian Weavile, but a new regional evolution.
I guess you can explain it that Hisuian Sneasel eventually adapted and became the Johto/Sinnoh Sneasel we know today; perhaps the new [old] form of Sneasel migrated to John through the Sinjoh Ruins. And because of the new form, it evolves into Weavile. Either that, or like the Galarian birds, Hisuian Sneasel and normal Sneasel are actually distinct species just named similarly and by the time DPPt comes around, Hisuian Sneasel has migrated out of the region.
Headcanon shit, I know...