I don't think there is a common philosophy. I've flown for many Boeing airlines and they had different ideas. One was where the pilot making an AFDS selection called the button pushed, and the other pilot confirmed it by calling the FMA. Automatic changeovers were called by PF and "checked" by PM.
Other airlines called the button pushed but DO NOT call the FMA's, only be aware of them, and DO NOT call auto changeovers, only be aware of them. Others DO NOT call button pushed but only the FMA changes. It is very much upto the C.P. I know of one training organisation, which has many customers, where they advocate the calling of all FMA's. They think, have observed, this leads to better crew awareness of what's going on. Boeing, I believe advocate a silent cockpit.