I think that DAZ will make future figures for DazStudio and improve these figures and DazStudio with new and better features.
But, as Poser is still a great commercial market, it would be wise for Daz to release two versions, one classic version for Poser and one with improved features for DazStudio.
The geometry,at least for many ling years, will continue to be triangles and quads, body parts can be added or removed, the same with materials and texture mapping will continue to be texture mapping, so all will remain the same for Poser, Daz or any other app.
What can change are the joint deformers and parameters and also the magnets and here the compatibilty will go away.
Probably Daz figures for DazStudio will bend better than Daz figures for Poser.
And if you want to use both Poser and DazStudio you will need to purchase both versions probably with some discount.

Stupidity also evolves!