People knew it was called iPhone OS internally, nobody cared because it makes sense considering iOS was literally iPhoneOS before iOS.
The first person who suddenly started saying iOS would be getting renamed to iphoneOS was Jon Prosser because clearly he didn't knew about this and everyone thought he had some weird insider info or something I guess.
This is the thing, Apple knew that the dude clearly didn’t know and they let him run around with it

Pretty hilarious.
It’s going to be interesting to see what comes true and what doesn’t in this next iPhone regarding the rumours.