I believe that a status of "backorder" means that the items are in the warehouse, but they won't ship until 5/14 when the collection launches publicly.
If an item has a shipping date that's after 5/14, that means the item isn't in stock in the warehouse, and this is the anticipated day of when it will come into inventory and then ship out.
If an item has a shipping date that's after 5/14, that means the item isn't in stock in the warehouse, and this is the anticipated day of when it will come into inventory and then ship out.