It does not seem to be the same problem. The link you shared is about linking OpenAL with a Xamarin.Android application without MonoGame.
If you have the same problem and try to use the AndroidNativeLibrary build action on the OpenAL libs in the MonoGame project, it will successfully build but you will have runtime errors when you call sound functions because the .so files will not be correctly embedded in the MonoGame.Framework.dll.
I still don’t have a clue about this issue besides trying a reinstall and I hope you will be able to sort this out too.
Thanks for digging into this.
EDIT: I just saw your post, it’s indeed the same problem but the mentionned link won’t help. 
I am going to check this with Xamarin as it’s not an isolated case.