https://wccftech.com/apple-is-still-selling-the-21-5-inch-and-27-inch-intel-imac-models-alongside-the-new-24-inch-one/

Although the new 24-inch iMac with M1 is the one you should buy, but Apple is still selling the Intel models with 21.5 and 27-inch displays.

It seems as though Apple has replaced the 21.5-inch iMac entirely with the new 24-inch iMac model with M1, but that is not the case. Right now, Apple is selling the 27-inch Intel iMac alongside the 21.5-inch model. You can find both those computers at this link.