In addition to the iMac changes, Apple has quietly adjusted many options for the iMac Pro, as Joe Rossignol reports:
Alongside a spec bump to standard iMac models, Apple today quietly added 256GB RAM and Radeon Pro Vega 64X graphics options to the iMac Pro.
Upgrading to 256GB of 2,666MHz DDR4 ECC memory will set you back a steep $5,200, more than the $4,999 price of the base iMac Pro itself. Radeon Pro Vega 64X graphics can be added for $700. Both are configure-to-order options.