The so-called "AI PC" is nothing more than a marketing gimmick. It has no new features, just a Copilot button on the keyboard and the same background editing function for web conferences that has been available for a long time.
DirectML is a low-level API that provides a common abstraction layer for hardware vendors to expose their machine learning accelerators. DirectML works with any DirectX 12-compatible device including GPUs and now NPUs. Support for Intel Core Ultra processors with Intel AI Boost was developed in close collaboration with Intel.