Disney Wiki has the opening date listed as Summer 2021, which would IMHO make sense in terms of an opening debut (it could open with the new Creations shop and the updated version of Club Cool) - I can't seem to find an official Disney source that gives an opening date, though.
Even with it being mostly related to something to do with your phone, there's probably going to be small additions around World Showcase as part of the experience. I wonder if some of the work being done in the Morocco Pavilion may be related?