You could say true Redaxe. We should take Bionicle and Castle as 2 differerents lines. Castle can't become bionicle. But Bionicle can diverstify it's range of creation: Bionicle, Castle, Pirats, etc.
There is no new castle (and pirats) set for a some years however (Except the blaksmith shop 3794, which can't be consider the same, because it's a MOC).
I'm thinking now that TLC stopped making Castle sets.
as they did with pirats some years ago.
And you are true when you said that Lego give us again great things, like Orient Express, Star Wars, etc.
We just have to hope.