The only news here is that Stripe is letting crypto companies use their various fiat processing services, now that they feel comfortable that they can legally do so. Confirmed by pc's comment [1]
The search trend, https://trends.google.com/trends/explore?date=all&q=Fiat%20M..., seems to be relative stable since start of collecting trend data (2004), with slightly increasing volume as we get closer to today, but generally stable.
More information: https://www.investopedia.com/terms/f/fiatmoney.asp
Bitcoin made the term fiat popular.
I don't think this is true, and I also provided a link to Google Trends proving this is not true (at least in terms of "Google Popularity"). Do you have any evidence that Bitcoin made that term popular?