This order was being talked about many months ago and seems to have happened. Rolls-Royce have announced that they have been awarded the engine contract. But, unless I missed it, the order was never announced on the Airbus website and is still not listed among their orders. Nor can I find it on the Air China website.
I've never heard of an engine manufacturer announcing a sale before the contract for airframes has been signed so what's going on? Have these planes been ordered or not and, if they have, why are Airbus so (uncharacteristically!) coy about it?