Comparing these two figures, I think you want to cancel the offset voltage of preamp and latch. but for conventional latch, when the latch works on 'nonlinear' .
. when the switch is 'on' and the latch is in 'reset', the latch output is all vdd(or a common mode voltage), so the input voltage opamp reset to vdd, the capacitors have not storage any offset information. so for conventional latch this structure can not cancel the preamp and latch offset.
if this structure can cancel the preamp and latch offset, the latch must design to work on linear region when the switches are 'on'.