Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed in the 2018.1.0.6714.1065 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.19/4.20 - Wwise 2018.1.0.6714.1065

• Added support for Unreal Engine 4.20.
• WG-30002 Added support for audio input using the Wwise Audio Input plug-in. See Audio Input.
• WG-33507 Exposed Event and SoundBank callbacks to Blueprint. See Using Callbacks in Blueprint for more information.
• WG-34570 Added ability to register to the global callback via delegates.
• WG-35615 At sound engine initialization time the floor plane can be set using a new value in AkInitSettings. The Audiokinetic Unreal integration sets this value, in AkAudioDevice.cpp, to use X-Y as the floor plane.
• WG-38608 Added experimental support for Lumin.
• WG-38676 Fixed: Changing Spatial Audio Volume shape makes Unreal Editor freeze.