User blog comment:Western Gen/Speculations for Season 12/@comment-166.205.68.47-20140122002023/@comment-4616231-20140122064251

Armor lock =/= excuse for retcon. It'd just be cheap.

If anything, Flowers might just appear in flashbacks or something, as his voice actor is their friend so they might not want to just cut him off completely.

Also Sister is dead, or may as well be by this point.