21.5-inch iMac Availability Dwindling at Apple Stores

The 21.5-inch iMac in both its non-4K and 4K offerings is experiencing dwindling availability at Apple Stores across the United States, with shipping dates for online orders of the non-4K model slipping by at least a week.
A vast majority of ‌Apple Stores‌ are listing the standard 21.5-inch ‌iMac‌ as unavailable for pickup. The higher-end configuration with 16GB of RAM and 1TB of Fusion Drive storage is currently unavailable for pickup entirely, but is available for delivery.