I do actually want to ask about these. I do agree that lessons can be learned from the main series games, but I had a somewhat different interpretation of what lessons could be learned from each game, and I'm curious about how you reached a few of the ones you mentioned
Kanto - I got a somewhat different message from this one (maybe it's because I played FRLG first). The rival was the one who was focused on really working hard and winning the league in the story, but lost not because of a lack of effort but instead due to a lack of care for his Pokemon. Similarly, Team Rocket as a villainous group are ultimately in the wrong because they exploit Pokemon. The applicable theme that I got therefore was that working together allows us to reach greater heights than we would separately (AKA team work makes the dream work)
Johto - I do get how you got to this one, given how big a role legends and the past play in Johto. Me personally, I interpret it as something more akin to "The passage of time is inevitable, so we should adapt and grow with those times while not forgetting our past", but that's way less snappy.
Hoenn - I think I flat out disagree with you on this one, unlike the previous two. Again, I'm looking at the remakes here, but I always saw it more as working with nature is better than working against. This is primarily supported by things like the Delta Episode, the design of cities like Fortree and Sootopolis, and even the secret base mechanic. I feel it's more in line with Aldo Leopold's work on the wild where we SHOULD be part of the natural world.
Sinnoh - I don't really see how you got this one. Is it because Cyrus wanted humanity to be "perfect" by removing emotion from the world? I can't really remember where perfection is brought up in these games, so please lmk!
Unova - Yeah, they were fairly on the nose with this one XD
Kalos - Also don't get this one. Is this based on Lysandre's motivation?
Alola - This one is... interesting. While the setting does feature a strong mix of past and present, ultimately I think the message and lessons are moreso built around Lillie's story arc of independence and being willing to blaze your own path. This is further supported by Kukui's push to start an Alolan league and the villains (the Aether Foundation) representing control, while team Skull were ultimately not evil due to being people trying to find their own way in a sense.
Galar - Is this one just cause Rose was like "Energy crisis 1000 years from now? Better take hasty action now to stop it"? Because if so, I can't really agree to it ngl, since it doesn't really have parallels elsewhere in the story that I know of. Happy to be corrected tho!