If you don’t have the market share that strategy makes no sense. You need to steal from the other brands. Having more phones available when peoples contracts are up leads to a higher likely hood of landing a sale.
That is not really how general consumers think. They want the next best thing when their contract is up. Having new phones come out with some frequency keeps the brand in consumers mind. Look at the IPhones market share. Why do you think it is dropping?
A lot of the phones Nokia releases are for specific carriers so its not guaranteed that the carrier you are on will get the next 15% better 932