Lecturers often discuss whether they should publish their slides before or after class. The argument against uploading them before class is that the students may then stay away from class, or that they do not take notes if the slides are available beforehand.
This is hardly true: If teaching as such does not deliver more than what can be read in a handout, the lecturer has a substantial problem. A presentation should only state the key points that the lecturer discusses in more detail and puts into perspective. Just going through the textbook material should be avoided – the students can and should read this themselves. Furthermore, the lecturer should not deliver solutions to problems that the students could have worked on/solved before class.
As to note taking, not all students take notes but learn well through reading (slides) and listening; many then write down what is important to them when working with the subject after class.
Publishing handouts before class can prevent the senseless note taking that we see repeatedly when students write each and every word that the lecturer utters in ‘shorthand’. Having the basic information in a handout, they can complement the contents in a far more constructive way. In English terms, they go from ‘note taking’ (senselessly writing in ‘shorthand’) to ‘note making’ (synthetising information).