I was wondering if they were going to apply the correction to all objects, but as they hinted at in the post, only objects old enough to cause a half meter shift will probably be corrected.
edit: right? It seemed credible, I only noticed the date at the end. The part where they would hide the edit from history was incredibly shady though, and that's what made me look even closer. I would hope they would never do this, if they even could. Without this part, the post would not have looked like an April Fools, just an actually good idea.
Edit: Oh, April Fools. Seemed doable.