Unlike the infamous Corrupted Blood plague in 2005, which caused mass deaths server-wide, the bug was not contagious to other characters. Infected Death Knights could only plague characters voluntarily, and as WoW Insider reports, "decided global extinction was the path to success when presented with the ability to enact it."
The Death Knight plague occurred only a day after Corrupted Blood's 7th anniversary on September 13th. A screenshot gallery of the plague's carnage is available at WoW Insider.
Trying to understand through signs and symbols, be it through inspiration in books, movies, ect, or through "glitches" in the matrix of our electrical/mechanical,or even the world at large, is a thought provoking enterprise. For a world caught up in the materialistic mindset, such thinking would be considered lunacy. But learning and knowledge is an ever expanding and all encompassing quest. Who knows when and where the next jump in awareness will be and from what source unless we keep all options open and put the pieces together.