Steam Welcome Gift:
Welcome Back, Hunter!:
From the title of this package, I'm guessing you receive the redemption code after a while of not playing DH, or a system just sends random codes to random players, so some players may receive it while others don't or have to wait for it.
An account named "_Santa" is giving away redemption codes on the forums + social media, it gives away these codes randomly at any time of the day within the event's time limit, like the DH Shoutbox for example.
Hope this helps!