Samsung is expected to launch a Galaxy S21 Fan Edition (or FE) later in 2021. This rumor is illustrated in new renders that suggest this putative affordable flagship variant will come with a rear panel much like that of the pre-existing S21 and may come in up to 5 different colors.
https://www.notebookcheck.net/New-Samsung-Galaxy-S21-FE-renders-show-a-range-of-colors-and-an-up-to-date-design.534141.0.html