For the lecturing portion of what a teacher does? Probably; YouTube's replaced/supplemented mediocre professors and tutors for a decade already on a number of subjects (e.g. math).
I hadn't considered using an LLM to practice my Japanese, but if it can spit out entire articles of mostly coherent language, it could probably serve as a practice conversational partner with reduced feelings of embarrassment for some people too. Doubt it'd be worse than the "split up into pairs (of non-native speakers trying to talk to each other despite insufficient vocabulary)" exercises that we had to do back when I was in school... Picking up an AI-nese accent would be a risk though, like learning too much of your Japanese from anime or your English from Hollywood movie trailers. (I didn't really understand that until I heard a guy on YT several years ago using the "In a world... where blah, blah, blah..." movie trailer cadence repeatedly as part of his plain old regular commentary. That was... enlightening.)
For the "babysitting" part of what teachers do? Probably not any time soon.