It does. But this is not just a game but a package consisting of the base game plus 4 DLCs.
Instead of doing how you do it you should either check if you own everything part of a giveaway before you enter (this is what the rules are asking you for).
If you still skip doing it, you at least should open the Steam store link of the giveaway on the won page before revealing the gift. That way you will immediately see if you own something or not (marked by the large green bar that tells you that you own a game or by indicators (on a package page like for this giveaway) that you already own individual parts of it. Only if you do not own it you should reveal the gift and move forward.
After all, if Steam has just a hiccup you redeem the gift thinking you didn't and the creator ends up with a non-working key they gift to someone else - and you potentially getting a permanent suspension for misuse of giveaway feedback. So... you get the point. Thanks for understanding.