As a data point I have noticed that since switching crediting flights from BAEC (where I am Gold/Emerald) to MPC (where I am Gold/Sapphire) about two months ago, the 'cabin crew greeting' no longer occurs on every flight. I assume this is mainly down to numbers (e.g. flights with loads of Golds/Sapphires they probably only have time to greet the Sapphires).
I also haven't had a single op'up since switching to MPC, whereas the rate was about 30% when I had my BAEC number in the booking.
Doesn't really bother me to be honest, the whole greeting thing gets a bit grating after a while (as I am normally already watching something on the IFE), although it is nice when flying Y when they bring you a pre-departure Cathay Delight!
However, in contrast I have never had a single op'up or cabin crew greeting with BA!