mine's from march 2022 (ordered within minutes after becoming available). I have it running for 12-18h per day since I got it. zero image retention so far (I hated my iMac 5K 2015 very much for having image retention). I'm using the built-in screen saver "Drift" with the option "Color: Silver". this might help to avoid image retention...
Even though I've only had this ASD for a couple months, as soon as I saw that photo of image retention I immediately went to dock settings and switched to automatically hide and show. Hopefully that will help down the road, and very glad for the option to do so.
I have the same image retention at the bottom of the screen. If I use any app with a static UI at the bottom, I still see the burned image of that UI after switching to another app. It happens after 5-10 minutes.
I don't have a Studio Display, but I have a similar issue going on my 27" iMac (Late 2017). On a more positive note, the retained image fades away in up to a few minutes rather than being burned in forever.