When a franchise becomes this huge, it becomes close to impossible to know what to change or what to do next. Obviously it's important to keep your old fans, but its equally as important to get new ones and the best way is by making a new entry to the series. So I'll just say I think these changes are "good enough". As an old fan of the Pokemon franchise, I don't want new generations anymore. The more they make new Pokemons and new regions, the farther it gets from feeling like a Pokemon. But I'm a realist, I think logically so I understand why they do this and I move on. As a premise, I was never a Pokemon game maniac by no means, I just like Pokemon because of the show I watched as a little kid. So I understand I am not the majority here, I don't have any nostalgic for the games.
I do want to give my opinion tho, which is that I want them to make a more "anime-style". What I mean by "anime-like" is simple. Just make it with bold outlines. I think the 2D-style was great for Pokemon because it was a lot closer to the anime or drawings you would see on Pokemon cards. Instead, they decided to use those plastic-looking 3d model with smooth edges with same looking animation. I always say, it's the eyes. When it comes to anything, the eyes are the most important, next to music. Music is responsible for 50% of the success, the eyes are responsible for the other half. The biggest issue in these new 3D Pokemon games are not graphics, story, designs, but the eyes, they aren't alive.