I don't know whether this is an oversight or an assumption that right clicking is enough indication of intention, but I just ran into a scenario where the confirmation pop up would have been prudent.

I was in icons view and had selected a bunch of files to open in a batch image processing app. Then I scrolled and selected a different file intending to open it in Krita, but I must have fat fingered it and hit the + in the top left corner, so without realising I had simply added to my current selection instead of making a new one - all other selected files were out of view so nothing appeared wrong. And because I had set an image viewer to open image files by default (for obvious reasons) I used the right click menu to open it in Krita...