I once installed an operating system from a CD-ROM which I later learned through an Internet forum that I could have downloaded from a mirror FTP site and loaded as an .iso into the flash memory of a USB drive for LiveUSB testing of the Linux distro, a new flavor of Ubuntu.
Out of the 52 words in this last sentence, 22 of them were new or adaptations, commonly through prescriptivism, and a common enough list of words that one can find each of them commonly used on the forum you're reading.
I conclude that your assertion that "prescriptivism rarely creates useful linguistic evolution" is wrong. While I doubt Facebook will shut down to honor the "not sharing intimate non-consensual photos" policy (as it should... as it shares data including photos without informed consent [EULA doesn't count in my personal view]), they aren't wrong to call out the common terminology doesn't work for setting a policy as it is too vague.
Out of the 52 words in this last sentence, 22 of them were new or adaptations, commonly through prescriptivism, and a common enough list of words that one can find each of them commonly used on the forum you're reading.
I conclude that your assertion that "prescriptivism rarely creates useful linguistic evolution" is wrong. While I doubt Facebook will shut down to honor the "not sharing intimate non-consensual photos" policy (as it should... as it shares data including photos without informed consent [EULA doesn't count in my personal view]), they aren't wrong to call out the common terminology doesn't work for setting a policy as it is too vague.
Have a good day.