Always love it, when a journalist or editor gets writer's block so bad, that they have to call Captain Obvious for help with a headline...
;>)
I see it this way: here’s a writer with just enough data to have a hunch, but not enough to actually back up a bold claim. So, instead of digging in, and doing the hard analysis that might yield the solid evidence needed to state the headline as a claim, they punted, and put it as a question, instead.