Apple worked with Pixar on USZD back in 2018 (making a file format around USD). This initiative is simply making an open consortium to guide the evolution of USD.
Apple has been preparing for the VisionPro for a long time. LIDAR makes zero sense on a smartphone, but was foundational. ARKit was foundational. A lot of their scene technologies were clearly targeting a headset, and smartphones were just a temporary kickoff.
It's pretty explicit at this point, the visionOS AR app model is centered around handing off content to a centralized renderer provided by Apple, and they've settled on USD and MaterialX as the ingest formats for that renderer.
