The CW's Riverdale is operating in a bit of uncharted territory, as the series has officially jumped forward seven years into the future. While that narrative decision has already caused some unexpected goofs on the show, it also has brought a lot of potential for new storytelling -- and according to new comments from showrunner Roberto Aguirre-Sacasa, that could potentially include cameo appearances from some of the series' sister shows. In a recent interview with Entertainment Tonight, Aguirre-Sacasa was asked if Chilling Adventures of Sabrina star Kiernan Shipka -- and by extension, any of the characters on either CAOS or Katy Keene -- could cross over into Riverdale.