It's a long-standing issue with librados, but the only thing that creates pools that matter right now is rgw. It'd be good to add another function that takes pg_num and maybe pgp_num too. Ideally it'd have some flags or other unused parameters that e.g. erasure coding and tiering could make use of. We can't remove functions because that breaks abis.

For this example, just a comment about the problem would be good enough for me.