You ARE confused. You are to prove a claim not a negative. You claim they lied. Prove it. I'm not even making any claims.
The default state: developer of the game says they have things in the game - therefore they have things in the game UNLESS PROVEN OTHERWISE.
But you know all that. It's just internet and you cannot accept being wrong.
It's good enough. Go to the steam page of the game and find me some multiplayer mentions in the game description.
Projecting much?