Maybe the manufacturers are gearing up for anticipated growth in demand and don't want to be left flatfooted when the orders start rolling in.
No. Employment is a lagging indicator of sales and occurs only after employers have utilized overtime options to satisfy existing demand.
Given that there has been no structural change in the factors that fuel a domestic economic environment that is hostile to manufacturing, I suspect this is just a temporary blip due to the decreased industrial capacity created by previous outsourcing. With no domestic regulatory reform on the horizon, I expect this blip will be followed by another downturn in future months.