World War Z: GOTY Edition comes bundled with a couple of goodies for those who either just bought the game or purchased the upgrade. While most of the advertised content is actually free to everyone, there are a handful of things locked behind the paywall.
Buying World War Z: GOTY Edition unlocks a new Chapter, Weapon Packs, and a couple Character Skin Packs.
All World War Z players have access to the Horde Mode, Challenge Mode, new weapons, additional missions added to the launch chapters, and extra difficulty settings. These were all added via free updates after launch, and while advertised with the GOTY Edition, they are all included in the game for everyone.
What World War Z: GOTY Edition locks behind the upgrade are a handful of things. The largest chunk of the paid content are the three missions in the new Marseilles chapter, and the four characters therein. Additionally, the GOTY Edition will grant access to the formerly Season Pass-only Weapon and Character Packs.
The Weapon Packs are more than cosmetic: these are top-of-the-line weapon upgrades that cost zero Supplies to use once you’ve unlocked them with the GOTY Edition (or from the Season Pass if you purchased that). These include the Lobo Weapon Pack, Biohazard Weapon Pack, Military Bundle Weapon Pack, the upcoming Last Aid Weapon Pack, plus 1 more upcoming weapon pack.
The Character Packs are purely cosmetic, and can be toggled on by customizing your characters between missions. The two packs included in the GOTY Edition are the Professionals Character Skin Pack and War Heroes Character Skin Pack.
World War Z: GOTY Edition has replaced the standard edition of the game, so all new players will have all of these things unlocked for use. Returning players either need to have purchased the Season Pass, or need to pay for the upgrade if they wish to access any of the paid content. There will be a new class added later this year, but it will drop as a free update not tied to owning the GOTY Edition. Worth noting: in a Private game the host can enable the new Chapter for their party, even if no one else owns it.