Blizzard clarified some Vault of the Incarnates raid bosses will drop better gear from the rest. In this week’s Dragonflight Beta build, they’ve given those items a separate tab in the raid’s loot window.
Very Rare Loot is comprised of singular items that will be +7 item levels higher from the rest of the loot. It is a very limited amount of items and unique items should therefore not be considered as Titanforging.
The Vaults raid only contains 4 Very Rare items as you can see below.