Yeah, I was really dismayed by that. It's especially bad because it's just so... meaningless. She dies for no reason, it's not really clear how or why it happened (when was the swap made, and how was it even possible with the Exiles keeping evil!Wanda under guard?), and maybe worst of all, nobody who loves her even knows it happened. Her friends and sister are totally oblivious. And with the series over, there's no possibility of them ever finding out, much less anything happening to redeem or avenge her or evil!Wanda ever getting her just desserts. Wanda was cool, and deserved better.