iMac Pro No Longer Custom Configurable, Available 'While Supplies Last'

Apple appears to be on the verge of discontinuing the iMac Pro, with the store page for the high-end all-in-one Mac including a "While supplies last" tagline and only the base model with no custom configurations available for purchase.
The ‌iMac Pro‌ launched in December 2017, and while there have been a few tweaks to the available configurations over the years, it has received no substantial hardware updates over its lifetime. As a result, we have been recommending for some time that