I think the sentence itself should be rewritten in a way that's more inline with available sources. The evidence for "skepticism" being widely applyied to "empirical skepticism" can be seen with a web search or a review of the sites and organizations which rally around this cause (Skeptic's Dictionary, Skeptical Enquirer, etc), but I've been unable to find a source that explicitly claims this, so this might fall under "original research." I am the one who originally added the sentence, so someone else should probably reword it.