Here, a false dichotomy means a distinction or a choice between two things that aren't actually either/or situations. In other words, with a false dichotomy, you think that you can only have one or the other, but in reality, you can actually have both. It doesn't mean that you always will have both, but it can happen. An example of a false dichotomy might be as follows:
"You can be successful or you can be happy."
Here, I'm telling you that you cannot be successful and happy at the same time. You can be successful OR you can be happy. This, of course, is not true. Many people who are successful are happy, and many happy people are successful.
In the paragraph you gave, the false dichotomy is between learning and play. This means that there is a false choice between learning and play–you either learn or play, and you can't have both. The paragraph is really saying that playing and learning can be the same thing, but instead, students are taught to prepare for tests instead of understand how the world around them works.
When children play, they understand the rules of their society and environment better, so a child can definitely learn and play at the same time.
Just like you can be successful and happy at the same time, you can learn and play at the same time too.
Society makes it seem like you can only play or only learn, but you can have both at the same time. That, my friend, is a false dichotomy.
Надеюсь что я помогал.)