Guerrilla Games Job listing provides insight on development of Horizon Zero Dawn 2. Also possible Online Multiplayer component in the works.

https://www.guerrilla-games.com

Listing: https://www.guerrilla-games.com/join/senior-game-programmer-1

Key points of this listing which was posted yesterday are,

"work together with the animation, core and combat design teams to implement the systemic and gameplay features of an epic open world game;"

"A wide range of in-game features such as ranged and melee weapons, combat and traversal mechanics, player skills, damage and hit responses, camera, inventory and economy systems;

"Implement new functionality for, and improve the Decima engine;"

Multiplayer?

https://www.guerrilla-games.com/join/game-server-engineer

"looking for a Game Server Engineer to support our Game Tech team with the project for an unannounced title."

This one indicates a possible online component to be released with HZD2 if that is there "unannounced title" as I believe it to be.

There is also mention of "Clans" and Tournaments being a gameplay feature for the Online portion;

"You will work on systems like matchmaking, tournaments, clans and leaderboards;"

Other job listings on their site include:

Senior Quest designer. https://www.guerrilla-games.com/join/senior-quest-designer-2

Principle Animator for living world. https://www.guerrilla-games.com/join/principal-animator-for-living-world-3

Senior Rendering Engineer. https://www.guerrilla-games.com/join/senior-rendering-engineer