No where in the report is there information about a 21.5 4K Retina iMac, despite the fact that there is 4K artwork hidden in an El Capitan beta’s code. But Kuo doesn’t say it won’t happen, it’s just simply not addressed in this report.
9to5Mac states that “the report says it expects Apple to use a phosphor material to significantly improve color saturation on the new iMac panels. Most models of the iMac range have been somewhat stagnating. Aside from the 27 inch Retina models and a cheaper low-end variant in August 2014, the lineup has not been updated since 2013. Hence, it’s not really a surprise that an update is reaching release. Kuo says Apple wants to launch the new iMac update in the current quarter.”
We’ll keep you posted on any news concerning this topic here and on Twitter.