User blog comment:KillRoy231/No no NO! Season 13 now?!/@comment-1031724-20160507161808

Also we're likely going to lose Castiel because Chuck/God said he's done helping Sam and Dean, meaning Castiel is either going to stay possessed by Lucifer or die along with him

I read something that implies Castiel is released from Lucifer's control but I think I misinterpreted it after reading something else.