My wrong: Yes it is not 10 mission but 10 mission trees for each of the two nations.The text speaks of 10 unique mission TREES each, not 10 missions.
Johan said that necessary game mechanic will be free while dlcs would be about specific nations and such if I remember correctly. They want to avoid paywalling stuff that is important like EUIV did.Paradox have been fairly consistent, moreso in recent times, in what type of content is free vs. paid for. The stuff in the free content pack is more towards the latter, so I don't mind it being described as free. Yeah it's marketing but that doesn't necessarily make it inaccurate.