Then the cofounder is referenced (not quoted) saying their goal is to create a social graph across groups by interest.
To me that sounds like a contradiction. How is this not selling users on privacy at the outset while intending to "convince" them down the road that privacy was never what they wanted?
The connections between groups only happens when people you get to know in one group start to build a real relationship that expands outside of that current group's context and lead to the creation of another group whether for another shared interest, or temporary event.
As people create more and more of these groups and these "mini-Facebooks" start to overlap users a new social graph starts to take shape not based on a 1 to 1 friend request but on real relationships, topics, and events.
As more of these groups are formed we aren't exposing what groups you are in to other people joining. In fact other people joining don't know who else is on the platform unless they are in a group with them.
So this social graph that is being built isn't based on friend requests that have little inherent value but on the different groups you are part of that are based on specific relationships.