Even now ChatGPT is pretty close to being able to tutor someone in a subject. You could build a product around it that would work off of a lesson plan, ask the student questions and determine if they answered correctly or not and be able to identify what part of their knowledge was missing and then create a lesson based around explaining that. It would need to have some capabilities that ChatGPT doesn't have by itself like storing the progress of the student, having some way of running a prepared prompt to kick off each lesson, and would probably require fine tuning the GPT model on examples of student-teacher interactions but all of that is well within the capabilities of a competent developer. I wouldn't be surprised if we see such a product come out in the next 12 months.

The great thing about a chatbot style LLM is that it can answer questions the student has about the lessons or assigned content. That's most of what a tutor is there for. It won't be as good at making modifications to the curriculum but you could work around that with some smart design e.g. evaluate the students response, if it's not great then expand on the lesson and ask more questions about the content to find out which parts the student doesn't understand then expand on those or provide additional resources as assignments, test and repeat.