AI respond to customer requests. They presumably responded to one from TAM. Why might they have done it? Because they were asked to do so.
No, PBL TAM did not ask for it. AB ofered it after the accident in Taipei but did not make it mandatory. TAM did not buy it. Now, of course they are saying that all their planes will have it.
I keep harping on it because, right or wrong this makes sense to me and because I like to know what can be done to prevent a fourth disaster like this one.
PS. Insofar as the letter from China I am waiting for my friend to get back at me to say what he has learned about it. I did not forget.