I chuckled at that. When I worked there I participated in no less than a dozen "super secret" projects. Stealth was the standard operating mode. In engineering I attributed it to the somewhat interesting way in which recognition and promotions were handed out, which was to say if someone else got word of your idea/project and executed on it more quickly they could declare victory and take the glory. So keeping things secret until success was assured was the "smart" play. And it didn't hurt than when things went south you didn't have to take the blame since nobody knew you were working on it. A win-win situation as they say.
Levy makes it sound like a big deal they were being super secret but really? I suspect it was keeping things that might, or might not, happen in the future from becoming part of the questions at a TGIF meeting.
What the re-organization has done has put a spotlight on how much Alphabet is a one trick pony. It's a good trick, and a strong pony, but it doesn't translate into other markets. And several other organizations have been training their ponies hard and are taking away that specialness.
The current road Alphabet is on doesn't seem to me to end in a happy place, so I continue to watch them to see if they will find a way to turn off it.