Sony shipped means the retailer has them in their warehouse. They're not on boats and planes. You think when Sony does their financial reports and reports the amount of consoles they shipped It's still being delivered? They've already been sold to retailers and are stocked. In PS5 case this generation, all are sold out. So shipped is sold.
The PS4 was also constantly sold out early on. Here's Sony's press release from April 2014 where they claim sell-through of 7.0m as of April 6th 2014:
PS4 shipments as of March 31st 2014 (so six days earlier) were reported to be 7.5m.