The title and your point are both just playing on the semantics of the words. The study is measuring "general intelligence", which is a better defined (if still poorly understood and somewhat controversial) subject amenable to scientific study. Basically everyone in the field accepts that it's real. Even informally, think back to your school peers: I'm willing to bet good money that, on balance, the ones that everyone called "smart" got the best grades, got the best test scores and ultimately got the best jobs. All those things are correlations, and they can be measured scientifically. And they're real.

Basically, if you want to quibble with the headline of the post, then I'll grant that it's a little confusing (intentionally so, as are most good headlines), even if IMHO that point is a little specious. If you really want to claim "there is no test that can accurately measure intelligence" as a matter of scientific fact, you're just plain wrong, sorry.