The official position is that all planes have been updated.

However, if any plane has issues, I would not be surprised at all if Iberia pulled an older plane out of a hangar somewhere to replace it temporarily.

One of the good things about both Iberia and BA is that you basically know what you're going to get. Many of the American airlines and the Middle East ones have a wide range of product - you might buy a ticket expecting one plane/config then find yourself on another. (with different responses to request for compensation due to a clearly inferior product)