The designs are really nice, but I feel they should be more differentiated. Otherwise you can't recognize a particular person by their avatar and you might as well use identical ones for all of them.
People are good at remembering faces, but this is for people who don’t want to use their face. I don’t think the goal is to be memorable, just an easy way to be mostly unique.
IMO, when used is real life scenarios actual users would start to find the unique patterns and visuals in each one. It is hard to evaluate this as a passive viewer with no vested interest in any of the names/avatars as they are presented.
Personally, I saw enough general distinctive qualities among them that I felt like if I interacted with a handful of these avatars frequently that I would notice the minor differences easily.