Definitely agree with Eric on this; code modernization is definitely on the risky side, so judicious updates are important. (Of course, not updating is also a risk, eventually. But not much of one in this case.)

This issue is really about whether the docs should be updated to use the newer syntax. In general, I think we should update the docs, and we've delayed long enough for the general application of f-strings.

There will be cases to be wary of, certainly. I'm thinking especially of calls to the logging methods, or anywhere else doing delayed formatting. (Not that I can think of others off the top of my head.)