Not sure when Tumblr was started, but I do know that Disney War made the exact same mistake of claiming that Beauty and the Beast originally had the Beast eating Belle thanks to her sisters, and that was made back in 2006, around the time Bob Iger was about to take over from the then-recently ousted Michael Eisner.
Also just because we are used to things ending tragically doesn’t mean it should. Think how cynical the world has become where enchanted castles and faeries aren’t what we consider far fetched but simply the idea of things ending well and yet things sometimes do end well in the real world. It’s not actually realistic to expect everything to always end poorly. Sometimes things really do end happily.