they could have done that before. chatGPT doesn't actually change anything. Don't you have an academic integrity policy?
also the teachers are using it to generate exams, so why not just let the sham arms race to the bottom run?
Students cheating is a failing of professorship, either your instruction, your workload, or others' workload. And/or students finding other things more worth their time while paying a lot to be there. which is still a failing of professorship.
I get that it's a hard thing to nail but the times are changing, change with them instead of teaching a style that hasn't changed since 1987.