> Is this whatsnew/3.8.rst entry correct and complete?

> The :func:`asyncio.coroutine` :term:`decorator` is deprecated and will be removed in version 3.10.  Instead of ``@asyncio.coroutine``, use :keyword:`async def` instead. (Contributed by Andrew Svetlov in :issue:`36921`.)

It looks to be fully consistent with the asyncio docs: https://docs.python.org/3/library/asyncio-task.html#generator-based-coroutines. From the blame of the documentation, it seems like Yury added the deprecation notice (GH-9314) to that section with the listed release for removal as 4.0, and then changed it to 3.10 (GH-9579). At a later date, Andrew implemented the actual deprecation (GH-13346).

So as far as I can tell, yes.