Information on the cameo
Gangsters dominated various cities who provided illegal commodity during the 1920s. Each major city had its own gangster element, but the most famous was Al Capone's Chicago Outfit members. These gangsters worked under Capone and earned money for him as well as working in the prohibition trade.
Appearance in the rap battle
The gangsters were seen inspecting a case of Al Capone's booze behind him during his first verse. Later, they were seen making a deal with Edward Kenway to kill Blackbeard's pirates, who had previously stolen their booze during Blackbeard's second verse. This is a reference to the Prohibition era in the United States, where the purchasing and selling of alcohol was illegal.