I really do wish they keep customization in, especially since it was my favorite feature in X/Y next to Amie, because it allowed the player to look like they're actually in the game rather than simply being stuck to a permanent default look the whole time and make it seem like you're not you but someone else, and that's the reason I liked customization because I could actually be my own trainer and not always be stuck with the default look all the time, all while on the PSS and in multiplayer people always see me as some trainer class like an Ace Trainer or something.
Customization is something I feel is very important in the games today. In a game that's in 3D, it shows that the technology is more possible to do and makes it easier to customize the player character, since it's clear they wouldn't just waste the effort of making the 3D models just to be stuck with a single outfit. Not to mention the franchise's international audience since you could choose your character's skin tone at the start of X/Y, after all, would a player of the games who's a non-white person want to play as a white guy the whole game? They'd rather play as someone who represents them than someone else because the player characters are supposed to be an avatar of the actual player.
So being able to change your wardrobe and being able to select your skin-tone gives both a sense of realism to the franchise and allows the player character to be more of an avatar of themselves rather than being more or less someone they aren't being stuck with only a single outfit like a cartoon character. Both these show that customization is necessary because it shows that the games are updating with the times.
Customization in the games has been requested for a long time, so it would be a shame if they take it out and went back to the status-quo of having just a single outfit to wear all because of some comments by Masuda saying it's a French cultural thing, after all, that's implying that only French people change their clothing while everyone in every other country just wears the same outfit every day like a cartoon character, so what he said kinda has some rather unfortunate implications there.