Yes, Ash does have an Alolan Vulpix that joined his team.
This particular Alolan Vulpix became part of Ash's roster after a specific incident where he assisted Ciel Phantomhive. During this encounter, Ash was tasked with locating five Alolan Vulpix that had escaped from a trainer named Keaka. Ash successfully found all five of the missing Vulpix. Following this, one of the recovered Alolan Vulpix formed a strong bond with Ash and subsequently joined his team with Ciel's permission.
