An insider with the nickname 有没有搞措 (@L0vetodream) / Twitter said that the new iMac with Apple Silicon system-on-chip would receive displays with a larger diagonal than the current line of all-in-ones.
21.5- and 27-inch models are now available for purchase. Many sources claim that the next generation iMac will finally get a new design. We can assume that the frames will be smaller, and the displays themselves will be larger.
Perhaps the top-end iMac will get a 32-inch display like the Apple Pro Display XDR. A small candy bar can get a 24-inch screen.
When the new monoblocks are shown is a mystery. The most appropriate event is the WWDC 2021 Developer Conference, held online from June 7-11.