It's probably not a new concept at all. In fact, I was introduced to something similar at a Rudolf Steiner school in Napier a few years ago. I understood it as this: The day is a series of tides: and they had moments of high tides and low tides - the activities would change depending on which tide phase they were in.
So I approached this year, with new learners, new to 'learner agency' and agentic learning by 'breathing in': structure, goal setting, independent learning and reflection. And then 'breathing out': inquiry based, student decision making, goal doing (where you actually practise or work towards the goals you have set) and reflection.
All learners have flourished this year and I think it has benefited them by having the breathing space of breathing in to internalise their learning.