I agree that the tool would be fantastic so it gets my vote, but just so you know (you probably do, but just to confirm) using creative commons license instead of standard means people can use YOUR video in any way they want, not that you're using creative commons to create your content. Or at least that's my understanding.
Changes to video attributions: The view attributions page will be discontinued after September 2021 due to limited usage. You can still add attribution to your videos by updating your video descrip
support.google.com
So because creative commons licenses can only be used on 100% original content, you wouldn't qualify for using that on reaction videos because reaction videos in their nature are reacting to OTHER people's content which you wouldn't be permitted to license, you'd only be able to use if THEY have a Creative Commons license set.
But overall I do like the idea of being able to mass change that setting if people were to make the mistake of setting it wrong unintentionally manually.