From the post:
Not sure where this is useful or why it's there, but if anyone uses this, let us know.
If you yabingle "quirky update", you'll find examples of its use - generally for doing things like running totals in the days before we had the windowing functions.
Is this behaviour specific to SQL version?
It's been around for aaaaages. It certainly pre-dates SQL 2012, as it was being used in speed phreak events in 2009 and earlier...