It's a debatable one in this case IMO. "There's a Persistent Hum in Windsor, Ontario, and No One Knows Why" tells me what I need to know -- it's a mysterious hu

It's a debatable one in this case IMO. "There's a Persistent Hum in Windsor, Ontario, and No One Knows Why" tells me what I need to know -- it's a mysterious hum akin to what I've read about many times, so there's little need to click. "There's a Persistent Hum in Windsor, Ontario" suggests it may be an article about a known cause/why there is a persistent hum, inducing me to click to find out the reason. A better solution might be to rephrase (e.g. "There's a Persistent Hum of Undetermined Origin in Windsor, Ontario") to avoid the clickbaity style phrasing, rather than just deleting the clause outright, but then you start editorialising which brings its own set of problems.