It hasn't been hush-hush, it's been a minor controversy for a while now. The "Tribute of Light" has been a bone of contention for some people, if you can believe it. It was going to be called "Towers of Light" originally and that caused a flap with the hypersensitive knuckleheads who thought it was wrong to "honor architecture" rather than the people who died in the buildings. So they caved and changed the name.
Before next Monday I fully expect another group to object to the SHAPE of the "Tribute" as too tower-like, therefore honoring architecture at the expense of humans.