I assume this alludes to their prior work with models running on smart TVs being able to setup inference on additional smart TVs. The idea being that you can't be sure that, having gone through the whole deployment process, your hardware has not been subverted to run a different model. Any level of "robust" code you can imagine to prevent this in the traditional ways could be subverted on the fly by a capable model.

> This moves unobservability layer to the system that collects the proofs.

I'd say it's adding security through a secondary system, rather than displacing security to a secondary system. Security by layers.