We have no choice.
The terms of the OGL are quite clear, we must operate according to the SRD.
If we use the gentleperson's agreement pre-release SRD for material, we have to adjust our products after the fact to use the released version when it is released.
By the way, what "revised SRD" are you talking about? I'm asuming you mean the final release of the SRD (since the monster & psionics sections of the SRD are still in pre-release and we are currently using them under the gentlepersons agreement until they go into final release).