I received the e-mail regarding the specializations. It gave me the code to unlock the specializations, and I entered it via my computer on the xbox website. I restarted my xbox and put in the Halo 4 disc. My specializations have not shown up yet. Does the code take effect immediately or do I have to wait a while longer?
https://forums.halowaypoint.com/yaf_postst155922_The-Official-Specializations-Email-Thread.aspx
Give that topic a read, it should answer your question.