I just found this from earlier in the year
“Regarding iMac, the poster said that the 2017 iMac update will not feature major external industrial design changes. However, the pipeline for 2018 currently suggests a major update. The 2018 iMac revision apparently uses more glass and a dark black finish. It would also re-introduce the glowing Apple logo as a micro-LED panel.”
Source -
https://9to5mac.com/2017/06/03/foxconn-insider-iphone-8-details-glasses-ar-siri/
Altho I don’t believe the bit about the Apple logo as a micro LED panel glowing. I also wonder if the dark black finish part is the person getting confused with the iMac Pro?