Yes, that is correct. I don't know about other schools, but first year students at Darden have 2 or 3 classes per day, generally 4 days a week often with some type of activity or a reading day on Fridays. Plus, you have a learning team to work with to prepare your cases for each day. It's up to each team how they like to spend their time (or whether to even continue working together). I'd say that 95% of the learning teams stick together at least through the recruiting season in January/February. At that point, some teams meet less frequently as people get the hang of preparing for classes, and because motivation levels go in different directions. In my personal experience, I spent a couple of hours preparing cases in the afternoon, and then an hour and a half with my learning team before each class day. Some learning teams regularly spent much longer together, but the individuals did less preparation on their own. Of course, if you read slowly, you might need more time to get through the material.
I'll try to share a little flavor of how the case method works (at Darden). Most classes begin with some background information - and could start with either volunteers or a cold-call. Anyone who has read the case will be able to handle this portion of the class, so getting cold called at this stage is only nerve-wracking for about 2 days. As the class progresses, you develop background and facts. Then, generally there is a second cold call where a person is asked to present the real meat of the case. Depending on the class, this could be a financial model or a balance sheet or some data analysis or strategic framework. This cold-call is tougher, and more the trickiest cases professors will actually ask for volunteers rather than cold-calling. The thing to remember is that you've already gone over this with your learning team the night before, so it's extremely rare that people will not have anything to present. Certainly, sometimes entire learning teams are wrong, and certain cases are designed to illustrate common mistakes (we have a data analysis case that demonstrates a very common modeling error) so having an incorrect answer doesn't mean that you will be penalized.
I think the Darden admissions process helps to identify people that will succeed in the system; for example I think the interview carries a lot of weight. If you come to Darden, you'll be surprised initially by how much everyone has to contribute - even the ones you think will be extremely quiet. As long as you put in the effort to prepare on your own and with your learning team (admitted students of course), you will not have a problem with class participation. If you get cold-called and didn't prepare anything, that's not good; and if you talk a lot without paying attention to the flow of the discussion or if you take the discussion backwards, that's not good either. But if you put in the effort to prepare, you'll be fine - even if you have more questions than answers.