I read Lockehart's post about not being able to play Hungary in the early campaign, so after I checked that I can confirm that is the case. Hungary doesn't appear in the early campaign.
However, I also know there is another bug in ETF and that's Hessen which doesn't exist in the late campaign.
This thread is about confirmed bugs in ETF 2.1.
Of course I haven't checked every nation (I prefer nation rather than faction) and if anyone can confirm a nation that has a similiar bug then feel free to post about it here.
Also, posting a picture as a confirmation is appreciated.