Changing teachers is a strange experience, for both teacher and student. For the student, there are different teaching techniques, (possibly) instruments, and studio enviroment. For the teacher, the first few lessons are generally devoted to determining what the student can do, and also what they can't.
Some teachers like to give an overview of their students to their successor. This is generally a good thing. However, I will never read such an overview before teaching a new student. Instead, I ask for any vitally important information (ADHD diagnosis, sensitivity to loud noises, etc.) separate to the overview. Then, in the first few lessons, I'll ask the student about their repertoire, strengths, weaknesses, what they enjoy about their instrument, and what they'd like to get out of lessons. For younger students, it's often something like "I want to finish this book", but it's sometimes surprising how specific young children can be regarding their desired learning outcomes. I would much rather ask a student, and have them reply "I don't know", rather than not ask, and then realise later (too late) that our goals were not aligned.
Additionally, I do not want my views on a student to be clouded by the biases (we all have them) of the previous teacher. I think I'm more likely to be able to make an informed view of a student based on a previous teacher's observations once I have taught them for a few weeks. And so I will accept, with thanks, the overview of a previous teacher. However, I'll keep it unopened until a few weeks in, at which point I think that I can make best use of it.