True, the article gives no basis to conclude that people searching "what is the EU" already know what it is, but it seems like a fair default position. I might search "history of the EU" or "Mitt Romney bio" to get a certain kind of content outside of current events and gossip. I could also see other people with similar (limited, but much greater than 0) knowledge searching "what is the EU" or "who is Mitt Romney" for exactly the same reasons.

The less clueless-sounding queries have spikes on Google Trends that appear very correlated with the "who is"/"what is" spikes, for what it's worth.