If it wasn't exposed, then they'd still be there.
I think she would've been happy but also not entirely as she would always wonder what it was like if she's still a royal. It seems to me that Margaret always liked being a royal. It's just that she didn't like being second fiddle. If she were in QE's place, it would've been so different. Her move would be watched and dictated everytime so imo, she's better off being second fiddle all things considered.