I call bullsh!t on this.
My three cats chase me around the house bumping me and nudging until I scritch and stroke them. I have one cat, Rooster (my namesake), that constantly rubs his head against my mouse control hand until I give up at the computer and rub him.
Purrhaps my control group is to small for conclusions. But as someone who has worked in the service of our feline overlords for many years, I would suggest these "experts" know not of what they speak.
They're probably the same ones who concluded that homosexual sodomy is natural, healthy and beneficial.
I have a cat that does that too...he gets on back of the couch and pushes my elbow, and if I don’t pay attentio....he will gum my arm! (He has no teeth) Trust me that’s most uncomfortable! You’d be amazed at the power behind those jawbones!...All so he can flop in my lap for a petting.