Just some feedback for your future contributions:

1. You can close conversations. Click on the "resolve conversation" button once you feel that you resolved the comment.
2. reStructuredText markup is a little tricky! So you can refer to the devguide for that https://devguide.python.org/documentation/markup/
3. I'll try to summarise what I look for in the Whats New deprecation. First you want to know exactly what is being affected (in this case the field of a certain struct being deprecated). Secondly, you want to know, without ambiguity, how we will notify users of this deprecation. In this case it's a compiler warning. Lastly, if there's a planned removal version for the deprecated thing, it should be mentioned too.

Thank you.

LGTM