The Reverse Falls timeline was added since the Gravity Falls arc of the series had concluded.
Regarding details to the Emily Clawthorne AU;
Emily was unable to stop Luz from taking revenge on Ms. Torigore and landing in the Detention track. This did, however, result in Amity becoming Luz's tutor and the rebel falling for the youngest Blight.
Graye wanted Cross to get close to Emily to spy on her, which led to him revealing his familial ties to her and Luz.
Cross stands in for Hunter during events where the later is off-duty but the Golden Guard still needs to make an appearance for publicity stunts.
