The "Selected X items" and "Select / deselect all results (all pages, YYY total)" only show up when there is pagination. This can actually be useful to see if you're filtering for all items referenced by another entity you've just entered and want to make sure you have all 64 or whatever. Lowering the amount of results before pagination is a hack, but can be annoying if you do want to skim results in the view.
Have a VBE view which doesn't hit pagination, but on which it'd be convenient to know how many items are selected - given that the info is already there most of the time people are used to seeing it and interacting with it.
Have an option to always show the number of results & items selected.
Closed: works as designed
4.2
Core