Quieter kids can speak up in chat,
As someone who was a 'quieter kid' at school, I disagree with this generalisation and think it brings into question other aspects of the argument.
Even today, taking part in an online chat I often don't bother to join in, particularly when comments are coming at a pace as anything I might say goes upscreen rapidly and may well get lost in the noise. That is no different in effect to being a small voice in a classroom, drowned out by those who are louder and/or more confident.
Another example that demonstrates a need for thinking it through more thoroughly, is the statement about having an international chat with his students and those wth poorer English using chat.
The fact that the students are there makes it evident that they have an interest and are engaged in the discourse.
I am sure that technology has a lot to offer education, it would be absurd to think it hasn't but it is not and will not be a full substitute for in person classes with a teacher at the head of the class.
My cousins, three of them, way back were educated by radio, living on a bazillion acre cattle station in the Northern Territory of Oz, the nearest school was a plane flight away or an expedition through the desert.
They struggled to get to uni' but did it because they were motivated and had parents who helped, without that motivation and family support I don't see distance learning working well on a long term basis for many students.