Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed in the 2016.1.2 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.11/4.12 - Wwise 2016.1.2

• WG-30304 Fixed: "Unload stream level" no longer posts a global "Stop All" to the SoundEngine.
• WG-30754 Fixed: FAkAudioDevice::PostEvent now always returns the playing ID.
• WG-30804 Fixed: Removed dependencies on the Wwise SDK samples. The new IO system now uses Unreal IO utilities only.