The feeling I get is "minimalist." Every Pokemon in Gen VIII has a specific gameplay purpose, so they are all one of the following:
1. A starter or its evolution
2. A regional Normal/Flying/Bug type early-game Pokemon or its evolution
3. A Gym Leader, rival, Champion or other important trainer's ace Pokemon or its evolution/pre-evolution
4. A Pokemon for the version exclusive Gym Leaders' teams
5. A Pokemon for Hop's team
6. A story-vital Legendary
I think the only three lines that don't fit in this are the Nickit, Yamper, and Silicobra lines; Perrserker; Indeedee; and the revived fossil abominations. Although, Nickit and Thievul seem to serve the role as "Pokemon for the villainous team," Yamper is Sonia's signature Pokemon (even though you never battle her) and is important for Milo's gym puzzle (i.e., they needed a sheep and a dog to chase the sheep, thus Wooloo and Yamper), Silicobra and Bolthund are used by Hop for one battle, and Sandaconda is an important part of Raihan's weather gimmick. That leaves only 6 Pokemon, less than 10% of the new Pokedex, that are absolutely extraneous to gameplay.
I don't know, you probably could do this with other generations as well, and maybe some of these categories are too broad. Also, admittedly, some of these are good design decisions. Making sure all the major trainers have a new Pokemon as an ace is a good design decision. But it's like they just checked the boxes they needed and didn't do anything other than that.
