This issue is discussed in some depth in my Ev. Psych. textbook: Evolutionary Psychology: The New Science of the Mind by David Buss. The Hazda women actually have a higher average WHR compared to the global average. Hazda men still prefer a WHR significantly lower than average for Hazda women.

Buss concludes by saying that preference for a low WHR is universal, but modulates somewhat based on the average WHR of local women. He also mentions that high-status men care more about WHR than low status men, which seems to fit obviously with the normal Ev. Psych account.