Has there been any rumors or statements from Facebook on them eventually stepping into selling cloud compute? I'd be surprised if they are investing in building hardware accelerators just for their own services.
Given that these chips seem to be power optimised and Facebook's recently released sensory model, I wouldn't be surprised to see them in their next iteration of VR devices.
The AI inference/training market is so competitive that I doubt enterprise sales is going to be the problem. A company planning on spending $50M training a model is not going to be convinced by some smooth talking sales guy over a golf game. They will look at the actual price/performance.