Open
Description
During imports containing guest-author posts, (especially staged or chunked imports) these posts can sometimes fail the get_post_exists check for a trivial reason: they differ only by post_date. To replicate, import a guest-author ... then change the post date, produce new wxr and import the same author again. A duplicate will appear. These duplicates are difficult to remove, since their slugs are the same.
It's a not--entirely-uncommon use case (I've found) to import CAP posts that differ only in post_date.
CAP posts that differ only in post date should be considered to be duplicates, perhaps by filtering the results of the check using wp_import_existing_post.
cc @ryanmarkel