The admin of a PeerTube instance can choose to auto follow other instances. Before, the majority of admins used this feature to automatically follow all the instances in the public index (which causes moderation issues). It is now possible for anyone to share a list of instances (on github, gitlab, pastebin, etc.) so that the admins of a PeerTube instance can use that list's web address to make their instance automatically follow the instances of that shared list. This lets users create auto follow lists within small groups.