It appears that way yes. But we still don't know for sure and I refuse to shout and complain when I don't know the full story.All the others platform have the DLC, so i think it's a problem with steam, right?
If it is Steam's fault and we end up waiting one extra day I will be a little annoyed but not massively. They haven't let me down before and I am happy that EUIV will be Steam only with lots of Steam features.