What country are you currently living in? I'd think they should definitely give you back the same machine you sent in (the only possible difference being that they'll probably slap a 2017 top case on your 2016 laptop). But I'd call Apple just to make sure, as some layouts are not offered as an option in every country. Worst case, the Danish keyboard might be a custom replacement part that might take a bit longer to get, but it should be possible.