Back when I first heard about this series I thought that it could very well be some big nostalgiafest with everything from previous sagas mattering, and indeed we have seen a lot of continuity, and I'm glad that it isn't just gen 1 pandering. My main concern right now is that they'll prioritize the most recent editions (XY & SM) along with OS.
I do like some of the worldbuilding editions like Lance having history with the Galarian Dragon gym, or adding varying Pokemon sizes like in GO and Let's Go, while feeling consistent with the fact that we've seen various sized Pokemon in the anime in the past. I do like that we occasionally see Pokemon from other generations in Kanto, but I don't like how they are restricted to showing up under the ownership of trainers, as opposed to BF showcasing newer Pokemon in Kanto without hesitation.
Then there's the matter of Ash and Gou. I think they both have great goals, but I don't like how they're being executed.
Most of the episodes where Gou catches a new Pokemon could just as easily be considered filler imo considering that the Pokemon are almost never the main focus. I also feel like most of his captures are a punch to the face to all the effort characters in previous sagas caught their Pokemon with varying levels of difficulty. I am however glad that they occasionally pay attention to this like when Gou caught the Lord.
Then there's Ash's goal. So far the most exciting WC battle for him was the first one, where he showed just as much skill and strategy as he has in other sagas. But my main gripe is that most of his WC battles happen very briefly or end at the beginning of the episode. Now, all previous sagas have done similar things with battles against COTD's that only take up part of the episode, and on one hand the fact that these are now WC might come across as being significant. However, my main gripe with this format is that it makes it seem as though Ash's goal is an afterthought, as though Ash's goal isn't even important to the series itself, which feels especially jarring considering this is supposedly supposed to be the tournament to end all tournaments, the greatest challenge in the world. Speaking of the which, something that concerns me for the future of the anime is what does Ash do next. I sincerely wonder what the series could do next to ensure that Ash doesn't move onto a goal that seems beneath the WC (unless this is supposedly Ash's last series, which it doesn't really feel like). Also from a plot wise standpoint it feels like Ash should be bringing back reserves just like he did for BF, but the main thing preventing him from doing that is the demographic of the audience.
Also when watching battles between the Master 8 to determine the strongest trainer, it almost feels as though there are no stakes, even though there absolutely should be considering their fighting for the honor of world champion. By comparison when Flint fought Cynthia in DP you could clearly see that they were going all out and that there was a level of intensity in that match because the stakes were so high.
Speaking of Ash and Gou, I do like the dynamic between the two of them, with Ash feeling like someone experienced at facing the world head on and supporting Gou as he tries to do the same.
I have varying thoughts about the lab. For one it feels like Ash actually has a reason to be there as opposed to the Pokemon school, with the Dragonite island episode being a prominent example of being an explorer/researcher. However, I feel like it's slowly starting to lose its purpose, as Ash and Gou are doing fewer and fewer research projects, and now the lab is just a home base, but hopefully future episodes will give it more meaning, which I do believe they will based off of the new opening.