Are they really repeating group dynamics this time though? Sure, BW was meant to evoke OS. Sure, XY has an AG feel to it. But how similar are the actual interactions?
For BW, I felt there was more of an equal friendship between the trio than in OS. Misty and Brock were significantly more knowledgeable and competent than Ash while Cilan and Iris were more on Ash's level; Iris being young and talented, Cilan being fairly competent but still learning and overcoming challenges. The group setup is similar, but the relationships weren't very.
It's early to say about XY, but they are definitely going the way of Advanced and hopefully learning from it. The Clemont/Bonnie relationship seems to be the most comparable to AG (though Bonnie doesn't seem to constantly sass Clemmy as Max did May). Doesn't seem like Ash will fight with Bonnie as much as he did with Max. Seems like he and Clemmy will probably have a brotherly relationship rather than a mentor/ward relationship. There is no significantly older companion/group chef/mama along this time, which will change things up. And it's easiest to have a four-person group if two are somehow related, and the easiest way to justify travel with a sibling is if the sibling is underage. idk.
There are certainly similarities, but it's the differences that make it interesting and there are plenty of those.