As the theme Default is not available in the admin’s themes page, for the theme Light I am selecting Theme is enabled by default
Hopefully this will make Light the new default and those who have not changed their theme setting will see the changes made by the added component themes as the component themes are included in the Light theme. 
The check mark, which was not present in any theme, is now present for the Light theme indicating, based on what I read, that it is the default theme.
