I studied my masters in Denmark 5 years ago, before AI. This was absolutely the case - first oral exams in my batchelors many of my fellow students were incredibly nervous. By the end the exam atmosphere was very chill. I definitely improved with public speaking, and so did the other students - including some who had been almost incapacitatingly anxious (throwing up, requiring a lot of convincing from us to even attend exams) and ended roughly the same as the rest of us