It’s unclear if Baseten is paying for this to be hosted, though two of their employees launched this. Baseten is a serverless backend for building ML-powered applications. Possible Facebook might argue by using the software to drive traffic to their commercial services, it is commercial use — especially if there were internal messages stating this was their intent.
I’m sure they want the test case on if model weights are subject to copyright to be two employees doing something in their free time and giving it away.