I would love a new protagonist for the anime, heck! I'd go back and watch it again if they did. Ash needs to retire, and he needs to soon, If what the guy in the interview said about pokémon being everlasting and there's plenty more anime to come after 5th gen, then I'd rather spend it with a new character rather than a overused 10 year old who's been 10 for 15 years.
Also, If they did put a new character in, wouldn't he/she go through the same cycle of being a new trainer, whom doesn't understand alot about being a trainer or how things work in the pokémon world, aiming to become champion/Pokémon master or a Co-ordinator.
Again, if they did add a new main hero, I would like to see an episdoe where him/her versus Ash, I'd think it would be 'absol'lutely amazing, but like, having Ash grown up! :D
Also:
Main characters of Pokémon Chronicles
Ash Ketchum
Brock
Casey
Jimmy
Gary Oak
I'm not gonna post the whole list, but I'm not seeing and
''new'' Characters here...
Casey was introduced in a earlier stage, and 'Jimmy' is a Anime version of 'Gold' or 'Ethan'.
I'm gonna be honest these to me are not new characters since they've been used before, I think what the Original poster is trying to put through is Brand NEW characters, that haven't been used nor seen before.
It would be great to see it in my opinion.