Professor Neil Selwyn,
The teaching profession doesn't "face" an impending change, that change has already started happening. University teaching has already flipped from being campus based to mostly online. However, most university lecturers will not admit this to themselves or to others. The higher levels of school will follow over the next few years. This is without AI, just using decades old e-learning technology.
Much of education can already be reliably provided by machines. This requires fewer, but more highly trained, teachers. What AI will not be able to do, at lest not well, is handle the exceptional situations.
Like human teachers, AI learns (that is why it is called "artificial intelligence"). Software is used to mimic human learning. Unlike a human, AI can learn from millions of cases very quickly. However, the results still need to be checked by a human as they can be unpredictable.
AI can minimc a human very effectively. The ELIZA natural language program of the 1960s was able to mimic a human in a conversation. It does not take much to do this, if the topic is limited to a narrow field, such as a course.
Like human teachers, some AI can explain its chain of reasoning, allowing the student to learn not just what to think, but how to.
AI can use a virtual face and body on screen, but in most cases this is not necessary. Most university students now learn online using text based materials. Where there are videos they watch them at high speed so any person visible is little more than a blur.
This is not to say AI will, or should, replace all human teachers. But AI will be used alongside other tools, such as writing and books, for teaching. It is a long time since anyone argued seriously that students should not write notes as they would then not be able to memorize, or that students should not read books, only listen to the teacher. In a few years time arguments against AI will seem as quaint as those against writing and books.