Besides, remember that at this point we shouldn't even be watching the anime. What is a repetitive thing for us, it's a "new" concept for the newer generations. I guess that's what matter to them.
However, Ash's goal can be put on the background and the writers can focus more on the other goals. In that way, they keep promoting the games, while giving a more original and exclusive story.
I don't think they will try something like that, but I believe that if they really want they can do that.