I am pretty sure they just reused Server names, that everyone was transferred to a new server using the old names.
^^ This. I have 3 of my characters on The Harbinger which have to be re-named but on the mouse-over, it says that the Harbinger is the "origin shard". So they sent all West Coast PVE to the same server and just re-used the name - The Harbinger - but we're all treated like we're first-timers to that server.
Why on Earth would they NOT explain this to people ahead of time? Talk about a PR mess. This whole thing is a complete mess. Instead of common first names and uncommon Legacy names....which would have made total sense.....we get the complete opposite. This whole thing smacks of horrible planning. They should have had everyone select a unique global name to identify them in the databases so that first names could be duplicated and then had legacy be a unique name.