From the full report referenced in the earlier article: When reporting data to the ITA for 2021, Amazon re-classified 393 facilities it had previously reported

From the full report referenced in the earlier article: When reporting data to the ITA for 2021, Amazon re-classified 393 facilities it had previously reported as operating in the General Warehouse and Storage NAICS Code (493110) as operating in the Couriers and Express Delivery Service NAICS Code (492110). Because there was no discernable change in the work processes at these facilities and because this reclassification would make year-over-year comparisons of Amazon’s safety performance challenging, for the purposes of this analysis, all Amazon warehouse and logistics operations that were classified in previous years as in the General Warehouse and Storage industry (NAICS 493110) were included in the 2021 analysis of Amazon’s overall injury rates. The trouble with the real world is that things don't fit nicely into perfectly square boxes. While it may be easy to imagine an ideal warehouse, the actual operation of a warehouse out there in the wild where things are far from ideal could look quite different, including having deliveries performed as part of its operation. As you can see, Amazon has found it itself teetering on a fence of what some of their operations even are in many cases. After all, if deliveries are not part of their warehousing operations, why would they reclassify some of their warehouses to delivery services when there was no discernible change in operation?