If it is the final design, then the case makers will have an easy day with carryover cases for the S22U. Better have a good price for me to jump to the 23 from the 22, and a new color I like.
Well it kind of depends if your s21 is running smoothly. Might not really be anything you need to upgrade but at the same time I will keep an eye on the trade and deals with Samsung cuz they tend to be very generous and let you upgrade to the newest phone at a really good price with some good bonus incentives