It's still possible these teams will be available later down the road, but the dev team does have new teams from the current edition of the game to tide fans over. While they aren't here now, fans can still hold out hope and talk with the dev team on social media. Based on what information is available now, it would appear that teams like Chaos Dwarfs, Lizardmen and Cyanide-created teams like Daemons of Khorne have missed the starting whistle.
When these games get announced, many speculate about what teams will make the initial cut this time, which always leads to some disappointment over the ones who will be DLC.