There's a third policy I've seen which is change in a commit immediately after a PyPI push. That works well with .devN releases but not so much once you're doing semantic versioning.

I think the bottom line is that there's no **harm** in bumping the version number, but it really only matters (and **must** be done) for PyPI releases. Whoever does the PyPI release should check that the version number has been bumped (and appropriately reflects semantic versioning).