The documentation sometimes suggests otherwise, but since there is no Python language specification, declaring something "part of the language" seems to have no

The documentation sometimes suggests otherwise, but since there is no Python language specification, declaring something "part of the language" seems to have no meaning if it's not "implemented in CPython". PyPy has had ordered dicts for longer than CPython, and Jython and IronPython don't look like they're ever going to support Python 3, so I'm not sure who this declaration is even even hypothetically relevant to.