The main problem is that without safeguards it becomes impossible to adjudicate new work in math or CS, meaning grad students who care about originality in work will have little sense of accomplishment if the AI gives them all the answers and will decide to study something else. Not to mention that AI users in math/CS are often ignoring standards in publishing, including issues with plagiarism and scooping of work. These are pretty serious problems that will end up causing a lot of people to move to other subjects.