As Ricky and Wes have pointed out, IDE refactoring tools are already able to look inside not just f-strings but regular strings too.
Ricky has written the opposite : "As far as I know, none of these tools know how to do the renaming of the FIRST bar to bar_new:", and i can confirm
If your point is a practical problem, it is already a practical problem for refactoring tools. How do they deal with this?
They don't do it automatically, so they give the burden to the user which has to review all the potential changes in strings literal (with a lot of false-positive, and some missing occurrences); and that's when they do, because mostly they don't.
That is why I am suggesting that tool users should start cooperating on a standard for directives.
Even if I agree with you on this point (for example, I'm happy that new versions of Pycharm support `# noqa` directive to disable some checks), this features makes it irrelevant IMO as I already stated that it would imply user repeating himself.