i don't think they are gonna allow chat gpt while giving the end semester exams, right? or quizzes/assignments? Unless there is some homework aspect to it, it still can act as a tool not a crutch. If student's use it as a crutch, then yeah they are not gonna do as well I presume.
This is EXACTLY what I remember people saying about Cell Phones and PDAs when they were popular in the 90s (people can't remember phone numbers any more), Google when it was first unleashed (people won't know how to use card catalogs and libraries any more), and then again about Wikipedia when it became popular. What actually happened was that behavior changed and people became more efficient with these better tools.