It’s best not to have a duplicate in queue, as it could be looked at as abuse; there have been past warnings/bans for submitting Wayspots/edits more than once, and there are even guidelines in regards to how many edits can be submitted for the same Wayspot at one time.
If the rejected appeal gets approved and the dupe is in queue, gets marked as a dupe and has the same main photo, it would add a copy of that photo to the database. There’s no need for more than one of a photo in the database.
And no info sign guarantees any Wayspot approval, nor do any specific country rules, as Wayfarer is global. There are plenty of cemeteries where I live in the US open to the public, like one that actually encourages the public to come see the wildlife that live there. Most though do not have any Wayspots, and this is typically out of respect for those buried there.