Given that Nikon only announced a general timeframe of March, it is unclear if Amazon’s changing of the date indicates that the camera will be delayed by about a week, or if they are simply speculating its release. Adorama’s listing still has it pegged for the 15th of March, while B&H’s listing has no date, save for saying that it will be available in March.
In any case even if it is a delay, we suppose a week isn’t really that big of a deal. Nikon has yet to confirm anything and so far, the only delayed Nikon camera that we are aware of is the Nikon D500, in which Nikon recently announced that the camera’s mid-March release has since been pushed to the end of April.
In any case the Nikon D5 is up for pre-order via all three retailers where it is priced at $6,500 for the body-only, so if you’d like to pre-order the camera regardless of its release date, then hit up any of the retailers to do so.