I can already tell it has to be one of the most boring books ever written, because there is nothing new there.
It is basically like writing a book that says: the sky is blue and water is wet.
For example, I’m currently reading 'Why We Sleep'. Obviously we all know that sleep is good for health, but reading the book gave me better ways to understand how good it is, analyze my own sleep quality and what I can do to improve it, and very importnat: show me how I can use ti to leverage other parts of life, like learning or emotional regulation. It’s not just “sleep 8 hours a day.”
So I imagine something similar might happen with her book, even if you already know some companies use questionable tactics, it can still be useful to understand those tactics, how companies avoid getting caught, how similar patterns might appear elsewhere, etc. It can also make you reflect on which limits are acceptable or unacceptable, depending on your political views.