Well let's imagine that John son of Christian II survives and succeed with support from his Habsburg relatives in gaining back Norway, so he become king of Norway, Christian III still end up in control of Denmark after his father Frederik I. Is this likely, not really, but it's possible, so that's our POD. Of course John II if Norway will have a lot of trouble, he will have to deal with a internal Protestant movement, potential rivals in the Church. He need to strengthen his position, if he marry late, a marriages with Mary Queen of Scots would have the greatest potential, as it would integrate two thinly populated minor states into a state which can rival Danish or Swedish population.
Linguistic it would make sense with Norwegian not being mostly replaced with Danish, but this is not given, without the Reformation and Lutheranism, literacy will be far lower, and there's unlikely to be a early standardization of Norwegian, which means that Danish writing and literature are likely to dominate even in TTL among the literate minority. In the longer run if Norway survive as a independent state, I think Janseism would likely have success in Norway (it seem the kind of doctrine fishermen likes). Norwegian surplus population would likely end up as mercenaries and settlers for the big Catholic powers of Europe. It could be pretty interesting to a few Norwegian speaking villages in Hungary by modern day. Potatoes are also likely to be introduced earlier to Norway, if they' re really lucky maybe Spanish sailors also introduce Quinoa.
