STILL CANON? So this definitely takes place at some point, and the Dick Slut Gang are now officially recurring antagonists in the RR universe, but it doesn't take place The Next Day. Like the other Bonus Comics, this one appeared in the printed Chapter 1 book, and the timeline got all reconfigured afterwards. 

Look forward to seeing them formally introduced in Chapter 2! Their leader is the guy with the pointy ears and his name is Artie (or...actually Arthur, but don't tell anybody that >:u)