Pretty sure that's just wishful thinking. Did his letter get brought up at Fox meetings? Possibly. Did it change minds? Not as likely as listening to the directors and writers who actually made Fox money in the past.
And, honestly, has Fox really changed that much that it's worth crowing about?
I'm sure that looking back on the library of shit they've produced over the past few years was alone a pretty big reason to get them to change their ways. I mean, when all you work towards is a big opening weekend, with no regard to quality, you better believe that impacts all the secondary markets (like DVD, cable, streaming, etc.) No one wants to buy/rent/license crap. Once fooled, twice shy after all.
Then again, we've yet to really see the fruits of this so-called turnaround at FOX, so I won't rush to any conclusions. I know I'm just speculating.