https://arstechnica.com/tech-policy/2020/03/with-demand-surging-amazon-signals-month-long-deliveries
As the coronavirus has forced millions of families into lockdown, demand for Amazon's delivery service has surged.
To help the company deal with rising demand, Amazon has prioritized several categories of essential items, including baby products, health items, and pet supplies.
[...] An Amazon spokesperson confirmed to Recode that these delivery dates weren't a technology glitch—Amazon has chosen to de-prioritize these items in the face of surging demand for more time-sensitive items.
[...] At the same time, Amazon is taking steps to increase its shipping capacity. As we reported last week, the online retailer announced that it was seeking to hire 100,000 additional workers to help cope with rising demand and was raising its minimum pay from $15 to $17 per hour.
(Score: 4, Insightful) by maxwell demon on Tuesday March 24 2020, @08:54AM
Keeping things in stock instead of delivering certainly costs Amazon money. Therefore I would bet that Amazon will ship something if it is in stock and it doesn't interfere with higher priority deliveries.
Note however that the prioritisation will likely not only affect the delivery, but also the restocking. That is, if the item you ordered is not still in stock, it will likely take longer to be available again. Obviously an item that's not in stock cannot be delivered, even if the truck still has space for it.
The Tao of math: The numbers you can count are not the real numbers.