https://arstechnica.com/gadgets/2023/11/apple-says-it-has-no-plans-to-update-the-27-inch-imac-with-apple-silicon-chips/

Apple's 27-inch iMac was one of the few Intel Macs (along with the iMac Pro) to be discontinued with no direct Apple Silicon replacement. It used to be Apple's mainstream workstation Mac, but in the Apple Silicon era, that role has been filled by the Mac mini and Mac Studio, instead. The 24-inch iMac, recently updated with a new M3 chip, is a smaller machine focused more on casual day-to-day computing.

Some 27-inch iMac users have been holding out for a true large-screened iMac replacement. But Apple threw cold water on those hopes in a statement given to the Verge (and later reiterated to Ars), where it said definitively that it was not working on an Apple Silicon version of the 27-inch iMac. Users of 27-inch Intel Macs should either move to the 24-inch iMac or to the M2 Pro Mac mini or the Mac Studio if they need more performance, according to Apple.