Answer
decreases
Work Step by Step
Total torque on point $A$ must be zero so:
$N_{Wo}\times L\sin \alpha _{0}-mg\dfrac {L}{2}\cos \alpha _{0}=0\Rightarrow N_{W0}=mg\dfrac {1}{2}\tan ^{-1}\alpha _{0}$
İf the ladder gets close to the wall, $α$ increases. This means $tanα$ will increase which means $N_{W0}$ will decrease.
