Confirmed,
I built the extractors using the latest 6.x revision and can't extract from a freshly downloaded enUS client:
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale enUS: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale koKR: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale frFR: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale deDE: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale zhCN: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale zhTW: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale esES: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale esMX: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale ruRU: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale ptBR: FILE_NOT_FOUND
error opening casc storage 'D:/Program Files\World of Warcraft 6.2.4\Data' locale itIT: FILE_NOT_FOUND
No locales detected