I believe they're probably trying to get the blog suspended (automatically?) hence the cache busting; chewing through higher than normal resources all of a sudden might do the trick even if it doesn't actually take it offline.
It is using the ?s= parameter which causes WordPress to initiate a search for a random string. This can result in high CPU usage, which I believe is one of the DoS vectors that works on hosted WordPress.
It occurred to me while reading the article that I could also just have checked the TLS cert. The cert I was given presents "Common Name tls.automattic.com". However, maybe someone will discover bgp.he.net via this :-)
