I remember hearing this episode on the radio some time back.
I am blessed to have worked in places where I haven't been exposed to many people who speak this way. I am surrounded by women, to be sure, but they are worried more about doing a good job than by trying to sound like it by deepening their voices.
It's funny, my mom is a non-native english speaker, having been in the US for 30 years. She heard a few women talking the other day using a well practiced combination of up-talk and vocal fry. She later turned to my wife and asked "Why are they talking like that?".
I do think that you will find that different demographics are more likely to speak this way. It's not the blanket category of "WOMEN". It's likely, from my experience, to be white, younger, professional women, and then, as knock-on effect, women from other backgrounds who work with them. They are probably plugged into the monoculture, have a common vocabulary, and use their vocal affects and vocabulary to filter out people who are not of a similar mind.
It's like when the newscasters all started speaking the same way, emphasizing certain words, movements of the head, a unique cadence that would, in conversation, be considered bizarre.
Nowadays, you are likely to dismiss any newscaster who doesn't speak that way as an amateur or charlatan who is not to be trusted.
Just my two cents. Feel free to give back change.