Background-color was set to be white, while Apple redefined the text-color to white too... So the texts where there! But white on white... Now they have a bit more contrast.
I did that to myself recently, while skin testing. Suddenly, the folder thumbnail captions had vanished! That was followed by 10 minutes of confused hunting for the hitherto undiscovered bug. Much gnashing of teeth. Eventually I realized that I was using a custom style that had a background image texture on the page, whose dominant color was pretty much the same as the caption text.