I think what they are trying to do is simply replace topic names with questions, to make it open ended and encouraging at the elementary level
so for example "Newtonian mechanics" is the topic, but the "Essential question" is (at the level of your children)...
“How do objects move?”
"Newtonian mechanics" doesn't really invite participation, discussion and thinking at the primary/secondary school level, its more intimidating than anything
if I were to front up to school to delivery a speech on "Newtonian mechanics" half the kids would probably turn off
but if I presented a topic on "why a torpedo kick goes straighter and farther" it would be just as relevant and more engaging for more people