The quote in context shows no conflict:

    In the face of ambiguity, refuse the temptation to guess.
    There should be one-- and preferably only one --obvious way to do it.
    Although that way may not be obvious at first unless you're Dutch.

It pretty clear that if you support python 3.6 you should use `f` strings.

> It pretty clear that if you support python 3.6 you should use `f` strings.

And if you support any earlier version of python, you cannot use f strings. Hence, there is a conflict between improvement and backward compatibility.

But for new projects, where you can chose the version of Python you want, there is no requirement for "backwards compatibility" - it's not as though Python 3.6 isn't available for every platform that 3.5 was on.