Hi there @bohanlon ,

Yes, disabling this permission will fully remove the student's abilities to create conferences in all spaces in Canvas. Since this permission doesn't have sub-options like some of the other permissions do where you can control where new conferences can be created, disabling this permission from the student role means you're fully eliminating their permission to create any web conferences. 

You are able to see more detailed information when clicking on the what it does header in the slide out information box.

I hope this helps!
Noah