Hey Gordon
Take this with a grain of salt, but generally the purpose of this and the other Wwise-something-Reference files seems to be to give access to all the
different objects in the Wwise project as Unity assets, which can be helpful in a number of ways. I think it was added to aid the WAAPI support added to the unity integration in 2018.1
They all contain the name of the object, and the ID, which means you now have a pretty accessible and stable way to reference these values, even if they change.
You can see these assets in Assets/Wwise/Resources.
Sorry if you were already aware of this ;-)
Kind Regards
Tobias