Why do I say that? Well, for one thing, because there are 8.11 million hits for "the lion shall lie down with the lamb". That's way too specific a search term for that many errant hits.
So at some point, we all got bumped into an alternate reality that's so close to the one we remember that we don't even notice the difference -- except with tiny, tiny details like that.
Or, if you believe the theory that we all actually exist inside a simulation, it means the sim got updated. We weren't supposed to notice, but the construct got updated while our memories didn't.
The Mandela Effect is a glitch in a sim update.