There's also this implicit conclusion that venting must not work if the levels of aggression don't change, but the article did say that blood pressure dropped. I thought the paragraphs on venting to friends didn't make much sense to me either--honestly, if something terrible happened to a friend, and they didn't vent to me about it, at least a little, I'd be wondering if we were still friends.
As an aside, I'd be curious to see the effects of venting on the subject as well as people that surround them. I'd also be curious to see the effects during a one-time episode and through repeated exposure.
I say that, because one of the worst things about social media is the venting. It's almost like folks are trying to suck you into a weird codependent relationship with them.