The Recent Edition of the Spoon 2DI Magazine contained a long interview with Series Director Jun Owada and Writer Deko Akao.
Here are some tidbits of what they both said.
Worldbuilding:
Executive Director Tomiyasu ordered the Staff to make the Series feel more like Pokemon in Humans World rather than in the flip way around.
The Entire Thing with Chewtle is nothing but a gag in the Staff Department. Tomiyasu just told Akao to write whatever she wants with one of her Favorite Pokemon in Episode 41.
Owada was told to direct PM when he was in the Middle of Koko Production. Meaning his takeover from Episode 55 was not planned from the beginning.
Progression of Characters according to Owada
Koharu:
Search for the future with Eevee
Future plots involving these two
Koharu and Eevee will meet more trainers and Pokémon with different goals
Koharu and Eevee will take the different routes of evolution more seriously
Goh:
Becoming more optimistic like Ash
Overcoming more struggles and development
Becoming independent of Ash as well as his equal and a more mature version of Goh
Ash:
Ash will become more unbeatable as the story goes on
Ash will begin taking more challenges
The essence of Ash is aim for greater heights and challenge more of the unknown
EDIT: Do note that I am not a Japanese Speaker so I rechecked all of these which were translated by somebody with another Translator on Twitter who gave me the Green Light before posting.
Chloe:
1. Meh, sometimes it feels like her entire character revolves around Eevee. Ex- Chloe episodes having Eevee being the focus.
2. Huge meh on Eevee's part, more Chloe is nice but Eevee's consistently shoved down our throats since XY, there's no escape!
3. Just give her a goal
4. Just sounds like repetitive filler: Chloe and Eevee meet so and so with Umbreon/Flareon/Jolteon/etc. I do hope they at least use Gary/Gladion for Umbreon, May for Glaceon, and Serena for Sylveon rather than introduce bland COTDs
I love Chloe but I don't care for Eevee!
Goh:
2. HAHAHAHAHAHAHA. More? That implies he HAS struggled. He just throws a ball and fails, not much to it! It's not like Ash, May and Dawn where they work their butts off to improve and overcome opponents like Gary/Paul, Drew, and Zoey. Hell even Sophocles struggled more than he has!
Ash:
1. ....that is literally a fanfic genre and
not a good one. Who wants an unbeatable protagonist? He won the Alola League, he didn't beat Lance or Cynthia, no reason he should be unstoppable. Ash not losing too much in SM works because there aren't exactly a mountain of experienced trainers there and the series along with the generation wasn't much battle focused. Him hardly losing is also why I actually hate XY, he never lost apart from the same individuals. Beat Tierno first try, curbstomped Sawyer multiple times until he somehow lost(for stupid reasons, that was utterly unacceptable!), only really lost against two gym leaders... the first and the last ones. It was the same deal with Serena, she only lost because of accidents and because Aria had a massive fanbase(aka rigged match lol). So it never felt like Serena lost because Shauna or Jessie simply did better(which they did), Serena lost because of an accident and never got to grow or improve. Just breezed through it!
Seriously just look at Smart Ash and stuff along that line, it's not good. His rivals are supposed to be the ones coming off as 'unbeatable', not him!
2. I sure hope so, more PWC episodes, the Galar League or
something please. Goh has THREE goals why can't Ash do something else?
3. Better be some actual stakes, Ash loses? He just regains everything offscreen so what's the point? It'd be cool if he actually had to regain it and go off to beat a prominent character somewhere like Flannery, a Galar Gym Leader, Sinnoh BF,
somebody! Not just skip to the next PWC and oh look, Ash regained his points somehow or is even further than he was before!
And his Pokemon magically showing off new moves throughout this series.... ugh. That just ain't right, it's fine if a Pokemon evolves and magically has new moves as that isn't unheard of there's not much challenge if Ash's Pokemon just show up with a new Pokemon. At least with Draco Meteor we could suppose that Ash was able to do so as he had experience with Gible. But why does Gengar know freaking Dazzling Gleam?! Ash never owned a Fairy Type and they ditched the much cooler Psychic! Why not lose Ice Punch? Plenty of Pokemon can learn Ice attacks lmao