Did you read the paper? They did not even track the ISIS pages. They had a small group of pages which they tracked and a control group (see the appendix)

They did not compare it to the news cycle, or consider that people are reading different pages about the same subject (AQ in Iraq for example being superseded by ISIS).

Sorry if I sound harsh but this study was terribly executed.

Doing it properly would require a lot more resources than Wikipedia daily page view dumps. I think the NY Times would be well placed to do a study on this using Wikipedia page views, their page views and their mentions of topics overtime.