I understand from where you are coming, yet I don't think it is fully accurate. To use your own example, after Chrom and Robin were explained by Sakurai, he specifically stated Robin had more of the "essence" of the series. That is completely confirming that the values of the world from which the characters come, the vocabulary, are greatly important. The fact that characters like Lucas and Ness, or the Star team, fight with great similarities, only furthers this idea- the characters do in fact represent their series, at least to some degree.
That said, they don't seem to primarily be chosen with this in mind. Though I do think that in some cases, such as Villager and Game and Watch, it is still an inarguable fact that they represent their series'.
I'd love for them to break the rules of evolution. Every time Eevee dies, it can evolve a new way which slightly changes it's characteristics. I think that is a fair balance of relating to the actual game, and also showing how important Evolution is within the Pokemon games. Eevee is constantly used for promotion, specifically to show off new ideas in the game. If gen 8 has more Eeveelutions, I see no reason it's day would not finally have arrived.
Meowth is also a constantly popular Pokemon. The fact that he is the second anime mascot will always help him to some degree. I do not think he will happen, but Pokemon, specifically stated to be different from other series in that the anime plays a key part of roster selection, will always have the option to add him. Especially if Sakurai finds a unique angle for him. Or has a sassy (Alola) form alt. That in itself is almost a reason he could be added for more effect.
That said- I would be curious to hear your perspective on my other points about why Fire Emblem transforms, and the fact that Mario and Pokemon do too, in the form of copious spinoffs.