It's also a bit weird, from the little I've seen.
Not just strict, but strange and strict — teaching unusual behaviours as desirable. The documentary I saw, a kid was instructed to stand there with crossed arms while talking to the teacher, which as body language goes, tends to communicate rude, dismissive, impatient aloofness more than respectful listening, in a 1–1 situation. My teachers wouldn't have been very happy about the message a kid was sending by standing there talking to them with crossed arms (though depending on the situation I'd guess they might let it slide), and that's good, because the rest of our society would potentially interpret it as rude or hostile too. I wonder how long it would take an autistic Michaela student to relearn how crossed arms can often be perceived socially, once they leave.
The kids in the documentary kept doing frankly odd-looking things they were clearly expected to do, like standing up (after a meal I think?) and gabbling shouted gratitudes, or doing peculiar rhythmic things when putting away their study materials.
I know it's minor, but I think that's one of the things that puts people off the idea of the school when they see documentaries — not so much the expectation that behaviour which is normally desired in schools will be very strictly enforced, but kids being systematically instructed and required to behave in ways that creep us out because they're unfamiliar and don't quite adhere to social norms.