From the snapshot notes:

• Wind Burst:
  • Unique enchantment which can only be found in Ominous Vaults
  • Has 3 levels
  • Maces enchanted with Wind Burst will emit a Wind Burst upon hitting an enemy, launching the attacker upward and enabling the linking of smash attacks one after the other
  • Each level will bounce the attacker higher up in the air

Contrast with the other two enchantments:

• Density:
  • Common Enchantment, accessible in the Enchanting Table and on Enchanted Books in loot

• Breach:
  • Rare Enchantment, accessible in the Enchanting Table and on Enchanted Books in loot

The Enchanting Table actually is able to apply Wind Burst.

Video: Mace Wind Burst.mp4

It may even announce it in the preview: