Probably will not happen, as they depend on the money from the recurring subscriptions to pay for development and new features. If it does happen i would be surprised.
I can tell you also from experience, even though a product is a lifetime product there are ways around it so people still pay.
For instance, lets just pretend for a moment Raidrive does have a lifetime plan you buy it and its currently version 2.0. You would get all the free updates and support for V2.0 and all minor revisions. Then Raidrive decides to release a V3.0 with all new features and and new internal workings. They could now charge a new lifetime plan license for it since its a new and updated version of the program.
That’s all fine and good of course you could choose to stick with V2.0 which would eventually become out of date from not being updated. With cloud storage, API’s change and get updated due. So eventually your V2.0 program would eventually stop working and you would be forced to update to 3.0. There are several companies that do this already with their programs.