I think it is assumed you will open a presentation in a separate tab and not need to 'return' anywhere.
You could argue that every link should open in a new tab by default and only replace the contents of the current tab in special cases, instead of the other way around. In the past 20 years we've been 'trained' to have different expectations, because of the design of the first websites, browsers and the resource limitations of those days. However, the designs and abilities of all of those have changed and it may be worthwhile to reconsider the current default.
You could argue that every link should open in a new tab by default and only replace the contents of the current tab in special cases, instead of the other way around. In the past 20 years we've been 'trained' to have different expectations, because of the design of the first websites, browsers and the resource limitations of those days. However, the designs and abilities of all of those have changed and it may be worthwhile to reconsider the current default.