Here are two articles Waze/Noam have tweeted today regarding the new closure feature. I assure you, most Champs did not know some of the details shared in the articles prior to today either. We aren't keeping info from anyone.
http://www.waze.com/blog/introducing-wa ... nexpected/
http://www.scientificamerican.com/artic ... -c-2013-02
http://bits.blogs.nytimes.com/2013/02/2 ... ads-close/
http://www.fastcoexist.com/1681469/waze ... n-steroids
http://gigaom.com/2013/02/27/waze-adds- ... id-update/
http://venturebeat.com/2013/02/27/waze- ... -its-maps/
http://www.wired.com/gadgetlab/2013/02/ ... p-updates/
And here's what I posted to the Android v3.6 thread regarding what I've gleaned from the articles so far.
Articles posted on the internets today suggest there is a critical mass of users who must report a road closed. There is some magical trickery which assigns what is referred to as a "trust value" to users. Maybe that's rank, who knows?! But fewer users of higher trust value are required to close a road and affect routing for all users. (This sounds a bit similar to users required to unapprove cameras from the use of the "Not there" button in the app.)