Cox was, along with Georgia teammate Robert Beal, charged with possession of marijuana after cannabis was found in their dorm room. It is, however, unclear if that incident had any connection to his dismissal.
There is no indication whether Cox will be eligible to play immediately. The NCAA has granted waivers to high profile transfers like Tate Martell (Ohio State to Miami), Justin Fields (Georgia to Ohio State) an Chris Steele (Florida to Oregon to USC) but the NCAA’s history with granting these waivers is spotty and inconsistent. Also, in 2018 the SEC lifted restrictions on intra-conference transfers but that is only for graduate transfers or players leaving a school under NCAA sanctions. Cox is not a graduate transfer and Georgia is not currently under NCAA sanctions, so by our understanding of the rule he would need to petition the SEC for a waiver as well as the NCAA to be eligible in 2019.