No -- no mistake there! I've been stalking them too since I returned some that had an open back. . .just waiting for these.
I tried them on in store (in different color) and foudn I did not need to size down in these. I have a wider foot, but not wide enough to need W.
They also have a fun red Mary Jane Fidji on sale. I wonder how those look in person and how they run. . .
I like oxfords on others but doubt I'd ever get enough wear out of any, so in my mind the Fidji's make a lot of sense Maybe you too?