Is it just a coincidence that the Ham repeater in Crestview has the W4AAZ call sign while the local FM goes by WAAZ?
Yes. The FCC divisions that assign broadcast and amateur callsigns are completely unrelated.
Although individual amateur operators or clubs can request so-called "vanity calls," and those can be based on anything, including a familiar broadcaster's call. For instance, if ham KB4ZYX retires from WAAZ after 40 years of loyal service or is just a big fan of WAAZ,that ham could request a change to W4AAZ as a sort of tribute if that call is available. If the FCC tells him that it isn't, then he could pick out another call or just stick with KB4ZYX. (The so-called "1 by 3" ham calls all were originally issued many decades ago, and most of the original holders have died. Clubs can hold on to them as long as they want, which is probably the case with the one that runs the W4AAZ repeater.
Hams consider the 1 by 3's more prestigious than the 2 by 3s, which have been around since the 1960s and are still being issued.)
Thanks for the information guys. I just happened upon a newspaper article today about the North Okaloosa Amateur Radio Club that listed the repeater's calls and frequency. Especially with the number 4 appearing similar to the letter A, it looks obvious that some ham wanted the W4AAZ calls.
If a ham has vanity calls issued, do the FCC issued calls (2 by 3) still apply in any way? Are they retired or put back in circulation?