The FDL has been used by the University since inception. I am positive it was used in sports as early as the late eighties. The administration was pushing the FDL as the primary logo at least five years ago when I was told that directly by someone in Martin Hall. Unfortunately there wasn't a big enough backbone to make the coaches all adhere.
Like I stated before I don't really see the issue. An FDL logo with a Ragin Cajuns moniker are not incompatible.