You're right, localization support is not part of the current integration, but it is part of our roadmap. I can't give a time estimate for when it will be done, though.
In the meantime, if you want to be able to generate your banks for the Arabic language from UE4, you can change one file in the integration. In AkAudioBankGenerationHelpers.cpp, in function WwiseBnkGenHelper::GenerateSoundBanks, there is the following code:
// Here you can specify languages, if no language is specified, all languages from the Wwise project.
// will be built.
CommandLineParams += TEXT(" -Language English(US)");
You can comment the line, and all languages available in your project should be generated.