On a personal level it would be a sad day if the calls are removed. I think they are very good for Situational Awareness and confirming the current (and correct mode). I have not heard much about this new silent philosophy depsite being very up to date with manufacturers guidelines but would be very interested in the reasons for the drive.
The buzzer in the cockpit canot be reduced in volume without a Flight Warning Computer (FWC) change. Airbus do offer this as an upgrade but if an airline wants this, the cost is a function of the airline/avionics support.
Hope this helps.
DTG