Yes, I see... I can't explain it sorry, either this was a special visit -as in "special guests" (ie architects or colleagues from another country) which from time to time, I know they have access to special areas of the SF to see how works are proceeding.... or it's a very recent addendum to the regular visit which I am not aware of. Again, while I try to be up-to-date on things happening in the city, I can't possibly cover everything, moreover noting I don't work in any tourist-related activity :)))
Note, however, this -the installation of the four bridges- is something that had been planned to be finished barely two weeks ago (end of May), and, knowing about the importance of SF here, I know for certain i'd be bound to become news when opening to the public... and I don't recall having seen it announced as such anywhere (press, TV....) so I'm a bit incredulous about being "open to the general public" as of now, despite the video. But again, I can be wrong, of course.
Sorry not to be more helpful here.