I watched the first video.
He's not wrong but I'm sure he is tailoring his teaching for his audience. I don't think he means that impermanence is exactly ch'i although that's what he said. This part of his talk is about stylistic differences between Zen and Vipassana and those are good examples. Viewing Zen practice as riding impermanence is very good and in this sense he is just talking about the energetic nature of Zen practice.
From one perspective impermanence clearly is ch'i flow. That's one example of impermanence albeit one not widely considered. He may have meant to say impermanence is the flow of ch'i. Correct but limited (but also visceral and direct).
So if his audience are Taoists, or internal martial artists or TCM practitioners this makes total sense. Also if he has restricted impermanence to the life process culminating with death (so the birth death cycle) then he's 100% correct since all changes to living beings occur as a result of ch'i flow and then finally the loss of ch'i.