They have cast a teenage Pope, Julia, and Baz. They won't show up until season 6 though.
Season 5 looks good so far. One thing I noticed about the trailer is no sign of Angela(she won't be missed) or Frankie (who was mildly interesting). Renn is there briefly but it looks like she might be in trouble. I hope she doesn't end up fridged she's the closest any of the boys has come to a viable likable love interest.
I think Pope saw Jay as a threat initially as competition for his place in Smurf's affections. (Darren had a similar reaction) He was just out of prison so when Jay showed up