I concur with Goldorak, it's far from guaranteed (IMO even unlikely) that SAS Plus will be converted to SAS Business when the change hits. It's much cheaper for SAS to downgrade people and pay out 30% of ticket price (which on short-haul is peanuts, especially for feeder flights) to those who complain than giving lounge access, priority security etc. to people who wouldn't have been entitled to it originally.