I would like to redirect requests for these resources to my CDN. Is there any reason to not do this?
The only reason that I can think of is that services that use them might not follow the redirect - it might not be transparent for them, they may have to actively do it, depending on their implementation.
The only way to know would be to try it out and test your intended use cases - do browsers still fetch them, what happens when you add the test site as a shortcut on a mobile device, etc...
