https://www.pcgamer.com/unravel-2-esrb-rating-hints-at-co-op-ahead-of-eas-e3-show/

In 2016, Electronic Arts announced that adorable puzzle-platformer Unravel was getting a sequel, but kept all the details close to its chest. Now, Unravel 2 has an ESRB rating that hints at co-op, which wasn't in the original.

The ESRB rating says that players will "control a pair of fantastical creatures called Yarnys". It's possible that the game will still be singleplayer and that you'll control two characters at once (like in Brothers: A Tale of Two Sons). But given the unstoppable rise of multiplayer, a co-op story seems more likely to me.