Honestly this could be a great addition if it was kept in the game forever. Just rotate the skins out every week like how the shop gets updated.
Imagine hopping on every week and 5 random new skins are discounted. The players would maybe be willing to spend their coins more often that way. Especially if there’s a skin they really want. It’s good for both the devs AND the players.
But knowing the OW Team, this Vault will probably only come around for 1 week every 6 months or something like that