@fribbledom ah, found an apparent clue: https://github.com/twitter/the-algorithm/blob/7f90d0ca342b928b479b512ec51ac2c3821f5922/home-mixer/server/src/main/scala/com/twitter/home_mixer/functional_component/feature_hydrator/RequestQueryFeatureHydrator.scala#L86-L93

These author ID lists are used purely for metrics collection. We track how often we are serving Tweets from these authors and how often their tweets are being impressed by users. This helps us validate in our A/B experimentation platform that we do not ship changes that negatively impacts one group over others.

is this actually true? eh, hard to say, but it's not the most unbelievable lie they could've published. I'm not the most fluent Scala user, but it looks like this is a from a hardcoded list fed in from outside or something.