They don't only should, they must change him. Enough of Ash, particularly since they have totally ruined it in the latests seasons. As the heroe of our childhood, he deserves a beautiful end, I mean, a end where he finally grows up and we see him becoming a champion or whatever they want, but then, stop with him. And then change the heroe, who could be ten if they want.
Or, I think it'll be a good idea if, Ash travelled for its part, and we followed the adventures of another former character, like May or Misty. Well, maybe not Brock because we also had enough of him I guess.
Or, an anime with Red instead of Ash. An anime based on PokéSpe. We can dream, can't we?