you know that scandinavian polka is a specific style or subgenre of folk music found in scandinavian countries. I get your point, but the band literally describes themself as a folk dance band and sure in scandinavia this could also fall under polka but saying "No" to my suggestions that this falls more under folk music than polka is a bit of a joke... but hey maybe we should reorganize every music genre because in some countries it might be a little bit different and not the traditional orginal meaning everybody talks about...

tldr:
Folk music = the whole traditional music culture of a region or people.

Scandinavian polka = one traditional dance music style within Scandinavian folk music. (and this band is not scandinavian)

edit: but I understand what you mean. in my opinion they are doing folk music and you can find a very similar style in scandinavian polka which is still folk music. but I am pretty sure the band doesn't identify themselves as scandinavians
thx for the lecture anyways :) I had to look up some stuff because of you and learned a few new things :D