Nevertheless, it's also React team that came up with prefixes like __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED in their codebase because people couldn't stop messing with the internals. So any documentation about the new compiler would be anything but rejected by the community.

Implementation details matter! Especially when reviewing the implementation.

While this is true, the fact that it is Rust provides a much greater level of confidence than if it was Python or something.