The way federation usually works is that a server will begin federating with another server once it encounters content from said other server. Therefore, instances on that list would’ve posted a post or comment or something on lemmygrad or on another instance seen by someone on lemmygrad, and that caused us to federate with them.
That would explain it. There are also a few instances that seem to be broken, so maybe they were added automatically
The way federation usually works is that a server will begin federating with another server once it encounters content from said other server. Therefore, instances on that list would’ve posted a post or comment or something on lemmygrad or on another instance seen by someone on lemmygrad, and that caused us to federate with them.