When a page is published from Author -> Publisher, the publisher see's
the resource as a new item added. You should be okay to use the
currentPage.jcr:created as this date can represent the last replicated
date. But however, just as a experiment for yourself, when looking at
the Author, the jcr:created is the actual creation date of when the page
was created (this date will neverchange), and you can actually find the
cq:lastReplicated, as this will be the actual lastReplication date.