If the lessons replaced are nothing but teacher-to-student lecturing then little is lost. However, all my best teachers employed more of a Socratic method. That method cannot be substituted with a recording. This program could work well with the Socratic method if students come to class to debate and present the material they studied at home.
Yes, which is the opposite of the proposal to have the teaching at home and the homework in class. But I think any distinctions are not helpful to the students.
In a good class there is no distinction between learning from the teacher and the teacher's assigned material because each is required to excel in critically debating and responding to the other.
I and my wife are educators among other things and want to try this. Please notify me at @mdhopkins or michael at oblique ideas dot com when you're testing.