Honestly, I think that this is a sham bid, and Norway intends to use this request to Sweden as leverage to get a better deal on the JSF.

That is what Eurofighter decided, when they withdrew from the competition.

Norway is arguably as hip deep in the JSF as any countries except for the UK, and (possibly) Italy.

Then again, if they are serious, Norway saves a lot of money, both on the initial purchase,the Gripen is the cheapest of the current generation, and over the life of the aircraft, since costs are roughly proportional to weight.