Not sure how this addresses some of the real concerns behind Recall, an example being if my password manager is open and showing data I don't want saved anywhere else.
On macOS (I assume a similar feature is on Windows) I believe an app/window can specify that it has secrets or is "private". I think is this what rewind.ai uses to skip capture, or maybe it's that the screen capture API's in macOS already filter out those private windows.