Although it does seem that some changes in WT doctrine and policy seem to be the result of comments and criticisms here, I have a hard time believing the GB members themselves spend any time on this forum.
Their narcissistic egos are way to fragile to handle the constant ridicule and attacks on pretty much everything about them.
The cognitive dissonance would be too great. They'd either have a complete breakdown or double-down on the party line: we're "mentally diseased" apostates under Satan's control.
Their public behavior confirms the latter: it is evidence that they are paranoid delusional psychopaths.