>>23596508
They can't. Season 6 uses a completely new animation engine incompatible with the previous animation, as well as having drastically changed the character designs so the stock footage there no longer matches the designs. Two of the character henshins that were only used once in the previous 5 seasons have already been completely redone in the new engine and used there when the characters transformed instead meaning any of the one use stock footage from the previous animation engine will never be used again