It has been several years since I worked on these myself so my memory is pretty poor on them, but U132 and U135 control the output as well, if I remember rightly they are used for over current, over voltage etc, so if they see a fault they shunt the gate drive to shut it off, you will notice all three device outputs are connected together through diodes.
I remember looking at those in my repairs years ago trying to trace a no output fault, I think in that case it ended up being a bad supervisor IC that checks the 5V supply rail, I showed that in one of the videos.