No, it's not what you think. Sadly.
However, it is replacing the previous starting weapon for new players. Before, you were given a slow-firing crossbow. Now? You get the Slug Thrower, a faster rifle-type firearm that uses the zip gun ammo, shared by pistols as well. As the type of players who enjoy getting fancy weapons early on in our character's life, this is a change we can fully support. Now, if only they'd make a gun that actually shot gastropod molluscs.