I believe, though may be wrong about this since I haven't been using
VoiceOver for a few years now that it is in deed possible to report what
items are selected on a list after selection is done. On Windows JAWS
can certainly report selected items on Windows Explorer list when
pressing JAWS+Shift_+Down arrow. For NVDA the same can be accomplished
with an add-on called Columns Review in this case the command to report
selected items is NVDA+Shift+Up arrow. This add-on is available from the
official add-ons website in the section for add-onns under development.