You can adapt a few things to work in a 2D Unity project, but things like AkEvent and AkAmbient seems to be designed primarily for 3D.
* That said, it's not uncommon to create a 3D unity project for your 2D game.
Attenuations: Should work perfectly fine. It's still based on the distance from the listener to the game object of that sound.
Effects (Reverb): You will still be able to apply all the same effects in Wwise, but the AkEnvironment won't work right out of the box.
So if you choose to use Wwise with a 2D Unity project, be ready for a bit of custom scripting (e.g. use Wwise-types instead of AkEvent/AkAmbient components), but it is certainly not impossible.
Does it make it more clear?