I think in the Deck13 co-op video, they made a correction statement that the equal guest can choose either world or character, but not both. Also, I think it’s a good idea to have public matchmaking.
They didn't say anything about random matchmaking but in the Deck 13 Co-OP video that was made some time ago. During video there was a option for matchmaking via invite. So I wonder if u can change that option to allow some one random. Just an observation I noticed.