Sorry if off topic, but I noticed that CPython doesn't deprecate macros in code, while with gcc/clang it's possible to show compiler warnings for them using some pragma magic:

$ gcc a.c
a.c: In function 'main':
a.c:29:13: warning: Deprecated pre-processor symbol
   29 |     PySomethingDeprecated (0);
      |             ^~~~~~~~~~~~~~~~~~
a.c:30:13: warning: Deprecated pre-processor symbol: replace with "SomethingCompletelyDifferent"
   30 |     PySomethingDeprecated2 (42);
      |             ^~~~~~~~~~~~~~~~~~~~

Here is how glib implements this for example: https://gist.github.com/lazka/4749c74249a3918a059d944040aca4a3

Maybe that makes getting rid of them easier in the long run?