The parliament (Stortinget) determines the guarantee amount. There are no political signals that the guarantee amount of NOK 2 million will change. The guarantee amount follows from the Financial Institutions Act.
It is nevertheless the case that the EU has proposed a common guarantee amount of 100,000 euros which is the same for all EU and EEA countries. Norway is an EEA country and the Norwegian authorities are therefore working with the EU to be allowed to keep the current guarantee level of NOK 2 million. If you want more information, you may contact the Ministry of Finance.