We have literally no information other than flag pictures and a very vague timeline. Maybe the DLC will be a lower cost to reflect having fewer maps and minor civs. USA and Mexico didn’t come with any. KotM was almost too much in terms of maps and minor civs. I would have preferred a bit less content that was of a higher quality like TAR.
But that being said, there’s a lot of potential maps that could be included along with Denmark.
Iceland is almost guaranteed, and Greenland would be an obvious inclusion. The Danes and Norwegians were prolific Arctic Explorers, so a lot of maps could come from there. For example, I’ve suggested Northwest Passage, Ungava, and Keewatin. Vitus Bering’s expeditions at the other side of the arctic also discovered the Aleutians. Scandinavia is also one of the bigger territories covered in Europe, so a few more maps like Fjords, Lapland, and Svalbard could be added there. If you consider their Viking legacy, regions like Labrador and Newfoundland also make sense. Both Poland and Denmark had Caribbean colonies, so another map in the region like Antilles would work. Africa was another region where both operated, but it was mostly in West Africa where there are already maps. Finally, Denmark controlled the Andaman Islands and some parts of India, so there could be more maps there, since regions like Coromandel or Malabar could be split off Deccan.
Even if you just limit it to maps in the Arctic region, that gives you the potential maps of:
Iceland
Greenland
Fjords
Lapland
Svalbard
Northwest Passage
Aleutians
Ungava
Keewatin
Labrador
Newfoundland
I’d be more than happy with a few new arctic maps plus a minor civ like Inuit. Plus it would be reasonable to expect a few more revolutions coming with Denmark and Poland. Norway and Ukraine are almost necessary, and maybe others like Liberia to represent their African colonies or Livonia to represent their Baltic territories. Poland could have revolution options like Ukraine, Romania, Haiti, Livonia, and Liberia. Denmark could have revolution options like Norway, Livonia, and Liberia.