No.  As someone building skis right now, that whole concept is ridiculous.
They molds in the ski press have rocker.  They all do it in basically the same way.
Bending it afterward would be incredibly unreliable, make the ski prone to failure (think about the force needed to bend the ski, hold it there, and have it stay in place), and would basically require that  every single ski have metal in it so that the bend would stay.
so no, salomon is not the only company who incorporates a rocker mold during press.  They all do (this is, unless, some companies have some secret super awesome bending machine I have never heard about).