Good question. Did they stop building them altogether during the war? I know they started using some wartime rationing tricks, ie painted handlebars, hubs, and truss rods to reduce chrome usage.
I never cease to be amazed, however, at the affect the war had on bicycle design and construction. Bikes were becoming SOOO flamboyant and nearly outlandish in their style coming up to 1940, then, they didn't simply pick up where they left off after the war, it's as if they had to reinvent the wheel, but it was never the same post-war. There were some some terrific and elaborate bikes after the war, but nothing like the Shelby Airflows, Elgin birds, or Huffman big tankers.