[According to the bug report, it seems this bug was actually fixed up in late February and likely packaged up in the feature-rich Chrome OS 65 update. We didn’t see it in the update notes, but that isn’t unusual: they don’t highlight everything for every update.
I routinely set my Display size to large after a powerwash, especially when I’m using Squid for a lengthy time. Today was one of those days, and I quickly noticed that things stayed put after I rotated the device accidentally. With that knowledge, I tested out the Samsung Chromebook Pro (still on 64) and noted the issue still persisted on that device. Chrome OS 65 has clearly fixed up this very annoying bug, and I am very excited for that. As I said prior, it simply makes the Android/Chrome OS environment feel so much more polished and native.