They already did. https://www.wired.com/story/amazon-warehouse-essential-goods...
> If you want to purchase, say, a hula hoop, you'll still get it as long as Amazon has them in stock.
So they're still selling non-essential stuffs, just not restocking their warehouse with them.
I agree that setting rules and transparency is a good thing - but a lot of that probably depends on the management at that particular warehouse.