Ash should have aged when they mentioned before that It was their one year anniversary since he began his journey with Pikachu. I thought that carried over with the past Seasons until BW first aired and hearing that he is still TEN. I can understand the writers are trying to appeal to newer generation kids, but they have this attitude when a new region is introduced, they think that their older viewers will not watch It and expects these newer kids to watch It. Therefore, instead of him aging, they still make him TEN. Here's what I have a problem with.
While you can keep him TEN for many years to come, eventually, you will come to the point where you can't do much with Ash's character anymore. Might as well throw him off the show and put a new protagonist in. By adjusting his age, maybe in his teen years (13+), they could open up to much more possibilities with Ash's character development. First, he needs to do the promises that he made with trainers he has met and that also includes Max. At the end of AG/BF, Max promised to Ash they would battle If he gets his first Pokemon. In order for that to happen, Max needs to age, so will Ash. It won't make sense If Max is 10 and Ash is 10. Second, It would open up to much more challenging battles. Maybe a much higher expectation than Gym battles? Why do I say this? Look at It this way, with him aging, he will become a much more experienced trainer. He will learn his mistakes and improve on that. Ash also wants to be a "Pokemon Master". How are you going to achieve this If you aren't going to age and not knowing what everyone was teaching him in the past? It seems like he goes to a new region and forgets everything of what he learned. So what's the point of becoming a Pokemon Master If you aren't going to look back on what those trainers/people have told you. This is why he constantly loses every Pokemon League Tournament. Because he is focused on winning that he doesn't want to come up with better strategies to help him win.
In all honestly, Pokemon has become a money grub franchise. These directors/writers/staff only care about making money and not caring about the story at all. Why bother? The Pokemon Anime storyline really needs fixing because Its a total mess right now. And the thing holding them back is Ash being TEN all the time.
Anyways, that's my opinion If Ash should age or not.