No, iPhones and beards are not a "thing."
Beards are a thing, but usually the type of man that goes for that angle is not the guy who would get an iPhone but rather an Android if anything.
Beards are like an anti-establishment/insecure type thing along the lines of tattoos. The guys are making a statement about existential pain and that deep rooted need inside to want to feel alive, but for those of us that are usually too shy to be deliberate about wanting attention.
iPhone is a about straightforward boldness. Clean shaven, you got the other cliche fashion of today which is the SS haircut.
Android is about anti-establishment so the beards would go for that if any such pattern were significant. (which it isn't.)
Now this is not to be confused with the "Ironic Hipster Beard" which is a totally different thing and, yes, would be iPhone side, but these are a lot more rare.
I think thats what OP mistook this pattern for.