Some teachers decide to release all lecture materials (e.g. prepared lecture notes, slides for presentations) at once at the beginning of the term, while some others release their materials gradually (i.e. releasing the lecture materials a few hours/days before the corresponding lecture), even though all materials are the same as the previous year.
What are the pedagogical advantages of not releasing all lecture materials at once at the beginning of the term?
I am especially interested in graduate-level computer science (machine learning) education in the US, in case the answer is country, field or level dependent.