Apple is currently transitioning from Intel processors to in-house chipsets based on the ARM architecture. The company has already moved three products over to Apple Silicon, and now Xcode has essentially confirmed that the iMac could soon follow suit. Rumour has it that the ARM-based iMac will feature a redesign too.
https://www.notebookcheck.net/Unreleased-iMac-with-an-Apple-Silicon-SoC-appears-on-Xcode.528177.0.html