We don't know how much it's used in exclusive titles.Had a look on umbra's web site
Found this quote
Again no mention of shape.
Betanumerical's info seems to be spot on from what i can gather
From what I remember (and may have changed by now), one of the two main audio middleware only used the mp3 decoding, same as ps4. They didn't sound like they had much interest in making use of any 'custom/unique' hardware, think they said they may look into gpgpu.
What MS should be doing is either writing some custom plugins/updating ones available, or get the first parties that use them to feed them back to the middleware etc.
As for Umbra, from what I remember about the QB presentation, they didn't go into what they did or didn't use in SHAPE, umbra isn't the audio software, they added some audio info to the data so it could be used for visibility AND audio propagation.
It would've been nice to have a deep dive into how SHAPE is used, that pretty much goes for any title at this point , especially exclusives.