As discussed on C API WG, formally soft-deprecate outdated macros:

• Py_LL & Py_ULL: Use LL/ULL suffixes.
• Py_MEMCPY (already soft-deprecated)
• Py_VA_COPY: Use va_copy directly.
• PY_LONG_LONG, PY_LLONG_MIN, PY_LLONG_MAX, PY_ULLONG_MAX, PY_INT32_T, PY_UINT32_T, PY_INT64_T, PY_UINT64_T, PY_SIZE_MAX: Use C99 types/limits
• Py_UNICODE_SIZE: Use sizeof(wchar_t) directly
• PY_FORMAT_SIZE_T: Use "z" directly
• Py_ALIGNED: Use _Alignas (C11) or alignas (C++ & C23) instead.

Plus Py_UNICODE_WIDE: soft-deprecate this instead of removing. (There's been no visible warning outside docs, and removing an #ifdef macro is indistinguishable from making it “false”.)

Linked PRs

• gh-146175: Soft-deprecate outdated macros; convert internal usage #146178