According to this site, the Galileo board is no longer support by Microsoft* since the new Windows 10 IoT image is available. Maybe they don’t let you download the other image because there is a new one available. Anyhow, you might get a better response if you post your question directly in their community: Windows IoT - Home
I think you answered my question pretty well.
I went ahead and ordered a Minnowboard Turbot since the Galileo won't do.