The companies whose deployment processes I've seen did exactly that - after an update, a request to a CDN results in a fault which forces the CDN to query the original company server. In those cases, the static assets had to be distributed onto the servers.

I would imagine Facebook does the same, but the article pretty explicitly says that they don't do that (which is why I imagine you got downvoted - for the record, I think that was inappropriate), which raises the question of what exactly do they do?

> The binary executable is just one part of the Facebook application stack, of course. Many external resources are referenced from Facebook pages, including JavaScript, CSS, and graphical assets. Those files are hosted on geographically distributed content delivery networks (CDNs).

It doesn't say whether or not these are part of the binary, but I'd suspect they aren't used as the CDN origin. You'd want these (randomly-but-uniquely named) resources to be pushed out to the CDN and warmed up before a deploy to avoid a thundering herd[1] problem from millions of users.

1: http://en.wikipedia.org/wiki/Thundering_herd_problem