KL/AF IT is mysterious. An example: I (PM), wife (GM) and son (no status) are booked together on a FCO-AMS segment booked through delta.com. PM and GM were automatically assigned to EC. But GM has extra luggage allowance, PM does not. Also, if you try and change the EC seat assignment you get the following message: "You got a paid seat for free. By changing seat you will loose this seat." (sic) and it wants to charge $26.51 for the seat change (from EC to EC).

So it seems to sort of recognize status. And as others have said, I have had success tweeting.