Most people make cursory updates to the body of the text as well. Like my sibling comment said, updating the date also helps your search engagement by showing a more recent date. That said it’s considered best practice to show the original and updated date.
I think the entire point is that it shouldn't "help search engagement" if it's an older article that's been "updated for present year" just to game search results.
>cursory updates to the body of the text
Still pretty straightforward to algorithmically determine if this has happened.
Why would that be surprising? When people search for something, they tend to want more recent info, more recent coverage, more recently made lists, etc.
