I haven't read The Infernal city but isn't Morrowind conquered by agonians and are made a part of Blackmarsh. If thats the case i think that if the next game features Blackmarsh then that game should also feature the argonian part of Morrowind if they don't change the provinces more to the next game

http://www.gamesas.com/index.php?/topic/1196628-official-beyond-skyrim/