Pokèmon always had sexy designs, imo.
At least, some games did it more than others: I don't remember her name, but the Ice Elite Four in Gen I whose name I don't remember is basically a stereotypical sexy teacher.
Then in Gen V there was Skyla who looked like a typical sexy cute character, the female trainer in Black had super short shorts...
But clearly now they are taking the bajillion of older fans in mind, and are doing it more and more explicitly. Sun & Moon is in the same situation as ORAS: more moe and sexy designs, more shirtless bara dudes. Check all the videos on the Pokèmon channel where they present new female characters, especially the sexy lab chicks and the rock gym leader, then read the comments section: I'm sure they are trying to cater to those people.
Some Pokèmon fans are perverts and furries; not all of them (there are many after all), but a good chunk loves their Gardevoir a bit too much. So it wouldn't even surprise me if the latest humanoid Pokèmon were made with them in mind. Some marketing strategies try to cater to niches as well, after all.
Also keep in mind Ken Sugimori is a huge otaku and I saw on his twitter that he bought hentai doujinshi and art books from a famous artist who draws a lot of moe lolicon (forgot his names, but he drew a game that was heavily advertised on 4chan called little witch romanesque), and keeps a shrine of Princess Peach merchandise.
All of this should speak for itself.
Edit
@Tyaren
The dude with the water pokèmon in the first pic is not from Sun & Moon, so the point is getting even stronger.