To be honest, I felt like there were waaaay too many Pelippers in Sun and Moon. With Drizzle and boosted water moves + hurricanes that never miss and have 30% confusion, Pelipper was a pain to constantly stumble upon in the wild and battle. It made training lower level Pokemons even more so annoying. I really hope we'll see more variety and fewer Pelippers in the upcoming games. What are some Pokémon you don't want to see?
In general, the rates of non-alolanPokemonn are pretty high, I would rather in the ocean we could surf into a lot more alolan Pokémon, at least in melemele, you can't even run into alolan Pokémon. If I had to choose one Pokémon though, it would be Gumshoos, and I dont mean remove it from the game, but later in game it is so annoying to keep on running into this Pokémon line since they are supposed to be starting Pokémon.
I think they should cut down on the Alolan Raticates. They are too common. Also, I agree with the previous two posts.
Yungoos/Gumshoos/Alolan Rattata/Alolan Raticate: I think I speak for everyone to say that they were WAY to common for my tastes. It's understandable that they're supposed to be rodent species, but the games show that their overpopulation is almost to the point of running rampant. I could probably count the routes on one of my hands where they can't be found. (Okay, maybe that's a bit of an exaggeration, but you get the point) Either remove it from some of the routes or reduce their encounter rates. Sucker Punch Raticates are annoying AF Spearow/Fearow: Same thing as previously stated. I went through a dozen Spearow encounters before I finally found my Rufflet. And Fearow pretty much dominates the entirety of Ula'ula and the post-game areas of Poni. Wingull/Pelipper: Same thing as previously stated. The good thing about Pelipper found on Poni Island is that they're good XP fodder if you can get past its Stockpile buildup. Cottonee/Petilil: They actually did a good job in keeping it to the meadows. I guess my complaint here would be that it's basically the most commonly found Pokémon wherever it's located. Trumbeak: The gripe here is its appearances on Poni Island. Why isn't it a Toucannon? I honestly don't want to see Basculin here. We already have Tentacool.
The sheer number of Hypno I had to go through to get myself a Tauros and Miltank was ridiculous. I'd love for Game Freak to lower that a bit, or at least make them a) have less annoying moves or b) give more XP. #MissingNo
Fewer gen 1 Pokémon in general would be nice. It feels like they've really been pandering to the gen 1 nostalgia train ever since 6th gen started. They kept it going with the Alolan forms. I don't dislike gen 1, but please, it's enough. Edit: So I was going to say originally that I would be okay with it as long as they didn't make it possible to just encounter the Kanto starters in the wild, but I decided against that because of course that wouldn't happen. That's never happened before. Well, nevermind, it's a thing now. It's not just the Kanto starters though, so I'm okay with it.