You will never know if others have previous flight experience. Most of the time this info is not divulged. If you want to prepare as best you can you should have some previous flight time. And no, it is not a lie.
I don't know about other primary classes, but for mine this was 100% NOT TRUE. Our flight leader specifically asked us as a class who had previous flight time (just out of curiosity). It wasn't a secret and no one cared, but it did come up casually.
It's not necessary and probably doesn't get you much of an advantage beyond a couple of the contact flights.