I just said there's a regulation and that tournament organizers can't completely do what they want.
The question of whose interests are taken into account in this regulation is another topic which has already been vastly debated in this forum.
are you sure your info in bold is up-to-date ?
In the articles I read in France in 2012, I read tournament organizers say that they had used the exact same surface and the exact same balls as the WTF this year, because of the ATP and top-players' request and the WTF being played right following week.
As far as I'm aware Paris still uses a different surface to London. It looks different visually too in terms of texture but that might be to do with the colours.