Muzdol,
Keep in mind that Sonar Platinum is gone, buried, 6 feet under the earth. BandLab doesn't have anything to do with Sonar, their product is call "Cakewalk by Bandlab" .
So, for lifetime updates for the product once know as Sonar Platinum, you will have to consult with Gibson about that, however, remember that Gibson ended Sonar Platinum. So according to the contract with Gibson, you will receive lifetime updates to Sonar Platinum as long as Sonar Platinum exist. Well News Flash, Sonar Platinum is no more as Gibson ended it's life.
Bandlab only is only responsible for the product, "Cakewalk by Bandlab", and they are not offering Life time updates, they are offering a free product..., it doesn't get any better that that.
Be happy and smile about the great news.