Re: Does unlocking Bangalores Prestige skin reset heirloom drop chances?

Yes, after their release events, all "mythic" (I sort of dislike this new term) items enter the mythic shop to buy with shards.

EDIT I misunderstood your question a bit.  No, after the event is over, you will not unlock the skin by crafting or buying all the items.  That's only for the two weeks of the event itself.