They've been perfecting technology to de-age actors, so they'll likely be able to do more in the near future, like just using an actor's likeness and voice to create computerized characters (with actors or estates paid licenses, of course). And beyond bluescreen and virtual sets, they'll likely be able to computer everything else, as well.
Given that, the problems won't be opportunities missed but the ff:
What new stories can they tell? At some point they'll end up like Walking Dead, Star Wars, Star Trek, Mad Max, and even Indiana Jones and more, i.e., with the same set of storylines but other characters, and generally melodrama (likely targetting the PG sweet spot) with action scenes but the same set of skins from the franchise.
Viewers will be saturated with same ole and will grow increasingly bored as producers try to milk franchises for what they've got. Probably hardcore fans and new viewers won't mind, but there won't be enough of them given so many new offerings per franchise plus franchises competing with each other.
