> So while my students are out on their walks, they might be mind-wandering more than in the classroom, but this is a good thing

To be a bit flippant, isn't this obvious? Who thinks that mind-wandering is a bad thing? Teachers, I guess. How is it possible to be a philosopher without mind-wandering?

> In 2014, a new study showed that walking decreased rational and linear thinking and increased divergent thinking and imaginative mind-wandering

The only thing problematic here is the decrease in "rational" thinking. I think in context it means something closer to rigid, concentrated, and well-defined (ie - uninspired).