Yeah, I thought that was odd. The presentation at the end of WandaVision seems to be that she realized that what she did was wrong and was on a redemptive path. But, the DarkHold has been shown to be extremely corrupting. Most but not all succumb to its influence: Aide is wholly corrupted, while Radcliff sees his errors in the end. I'm thinking that the presentation at the end of WandaVision was of her reading from the DarkHold, while projecting an external "normal" scene. I had thought that to be her sitting outside her house while having an astral projection read the DarkHold. That ending scene wasn't clear enough in foreshadowing Wanda's corruption.
To me, a weakness is the gap between the end of WandaVision and Wanda's appearance in the movie. While I understand the movie is already quite long, the transition is not adequately presented. I wonder how folks who have not seen WandaVision will handle the transition. There is too much which is not explained unless WandaVision has been seen. I think some showing of Wanda gradually becoming worse and worse are needed. The scene with her and the boys is too small to explain what happened, and feel disconnected. Who are these boys? Where did they come from?