To be fair from what I could get out of the French Wiki page, it says 12 for the release in theaters and 16 for TV.

Also I've skimmed through the movie and there's a scene where a girl is posing nude for an art class and you can see genitalia.

I haven't seen the movie, just a single scene that someone posted on Twitter.
Netflix, the producers etc. can claim that the movie is actually about XY as much as they want; as others have already pointed out:

It's the constant close-up-shots that are so revealing.

Those close-up-shots make perfectly clear that the producers intentionally tried to fulfill the desires of pedophiles. Claiming that the movie is actually about cultural clashes of immigrants or whatever is about as credible as claiming that the famous german "Warum liegt denn da Stroh rum?"-porn movie is really all about pointing out the dangers of storing straw next to fuse boxes.

The problem with this movie is that actual pedophiles now have a legal movie they can watch to get their fix. Like what they hell. I'll never watch this shit movie but this just seems like content for pedos to watch rather than anything else. I hope no other movie like this gets made. I don't want pedos to have legal movies to watch on Netflix or any other service. And I don't think 11 or 12 or 13 year olds can give consent to film makers to film their private parts so in that sense it's kinda disgusting and amoral on the filmmakers part and even maybe grounds for legal action. I mean just hunk about the actors and what they'll think about it 10 years down the line? The entire damn movie is just bad news. The film makers spent hours making a movie that has scenes with closeups of kids private parts and them doing weird dance moves that provides legal content for predophiles to watch. The FBI and agencies around the world should watch out for people who keep rewatching this movie too many damn times..I can't believe who thought this was a good idea.

If the purpose really is to criticize the sexualization of children, the point could have been made without having these elongated dance scenes, and several of them. Can't help but feel that this was done for the pleasure of some people. I don't like it. And I don't want to be the slippery slope guy, but I worry what kinds of doors this kind of thing will open for future films.
By the way, has there been any Muslim outrage about this? One would think there would be cities on fire by now.

I usually am very lax concerning nudity and sex in movies. Who cares if some girls are dancing around.
On the other hand, pedophiles care. And this might be a problem. But honestly, perhaps it is not. I'm just thinking out loud here. Pedophiles are sick people, they are ill and need help. It is often tragic how they cannot help themselves with their pathologic sexuality. There is an awesome movie with Kevin Bacon playing a self-hating pedophile.
Perhaps having such a movie can be an outlet for sick people. I'm not outright saying that the movie will prevent sexual abuse of children, just musing how it can perhaps also have a positive/mitigating effect on people who cannot escape themselves. But I don't know the first thing about psychology. Could be that seeing such pictures drives the desire up in pedos.

If there were no pedos in the world, I would probably have no particular problems with the sexual things in this movie. But I surely have to watch it first.

The last thing I will say is this: Everybody who thinks children have no sexuality is sorely mistaken. It is part of you from the very beginning. It just changes over time for your whole life.

On the contrary, nudity from adults shouldn't be a big deal for age ratings. A body is just a body and as adults they gave their consent, there is nothing wrong with a naked body. It is the excessive blood and violence that should be completely restricted, I think most people can agree that murder and excessive violence are not okay.

I thought this, until I saw camera zooms on 11 year olds spreading their crotches and slapping eachother on the ass, bending over etc.

Yeah, 10 and 11 is a bit of a grey area. I myself was very sexually interested already when I was 10. However if you go down in single digits they definitely are asexual. To a point where you could show them explicit porn and they wouldn't know what to do with it.

Anyhow, the time at which children are introduced to sexuality is irrelevant. Children shouldn't be shielded at all. Because if you do you will get completely screwed up adults claiming everything is perverse and pedophilia. Hell, I'd wager that at least 90% of people who use that word don't know what it actually is.

Is there any objective reason why that would be a bad thing? I mean if it makes you uncomfortable for any reason, that's fine. Watching horror movies makes me uncomfortable, which is why I don't watch them. However no one seems to want to boycott them.

Yes but horror movies aren't real portrayals. It would be different if it was an older actress pretending to be younger. But they're actual children, bending over with camera zooms on their actual child bodies spreading their legs etc. 

I don't mind horror movies with murder but you don't want to watch a real snuff movie.