Due to the active bombing campaign against the civilian population, many Palestinians are wounded before they are starved.

About 2% of Gazans have died from the war (including militants etc), so that could maybe explain a 2% difference, like perhaps there was a 42nd person who was going to die of starvation but was bombed first. I don't see how it would explain more than that, and 42 is still quite far from 63k.