I would expect that many modules may have this issue. If it was never being checked, I bet it’s common to add something new to a module config (especially conditionalResources) and forget to change the configVersion.
Is this also because we dont always add a DOCTYPE to the config.xml pointing to the xml definition files? This way I assume we would at least see that we are adding some element in the xml that is not there in the version we currently refer to.