Your initial assertion was that it was a new term, ergo it had not been used in ANY source until very recently.
Is this true? No, as my evidence clearly demonstrates.
You now have changed your assertion to be that it hadn't been used in any mainstream media source until 2015.
Is this true? Not really. It became widely used in 2016, but there are (infrequent) references to it dating back to at least 2004
https://trends.google.com/trends/explore?date=all&geo=US&q=%2Fm%2F01tg30