Yup, this is a great win for free software as proprietary modules have less leeway to call GPL functions.
As an opt-in measure under the control of the user these changes are not unreasonable for certain security contexts, but to the extent that they prevent users from loading the modules they wish to load—including anything (not just proprietary code!) that needs to call arbitrary kernel functions via dynamic dispatch—it's user-hostile and contrary to the principles of free software, not anything to celebrate over.