I'm not sure there was ever an actual timetable for retirement and even if there was one internally, it must be in tatters with the 787-900 engine issues. Virgin leased the Air Berlin A330s and even un-retired Sleeping Beauty in early 2018 to cover for the Dreamliners so until that issue is fixed and proven to be fixed (see the newly uncovered problems with 787-1000 engines) I wouldn't expect to see any retirement announcements.