Judging by the Reddit threads I saw, A LOT of people were upset even though it was clear that they had not idea what the feature actually provided beyond “encryption”. I’d guess that the majority assumed that the change would result in them basically having to “encryption” in affected AMD devices any more in some vague general sense.

Exactly. Thus far I've seen 1 person use it...and they seemed to believe it provides rowhammer benefit...so somewhat tangential