That's not because the language was alive until that time
at that time (1971), Dr. Emil maher finished (or was finishing) his Master research about the old pronunciation issue
and it seems to me that at this time Pope Shenouda was very big supporter and willing to return the Old pronunciation back (that he started pronouncing some words in old pronunciation ?)
but at some point and for some reasons I am not sure of, his enthusiasm cooled off
anyway, it would be very cool if you could put those records on mp3 files
and either give us link, or give it to me to upload it