El Salvador has adopted Bitcoin as a currency and it has not led to the spread of the same policy to neighbouring countries.
There is a small indirect effect of El Salvador adoption of bitcoin on Javier Milei policy on bitcoin. If bitcoin were not having a positive effect on the economy and people in El Salvador, I don't think that Javier Milei would sanction it in Argentina. At leas El Salvador served as a real life case study for them. According to
Chiananalysis these south-american nations have the most active crypto communities and if think if they play their cards right, we may we one or two of them being the next up for adopting bitcoin - Venezula, Brazil, Colombia, Mexico, Argentina(already in the course of it).
This might be the first official case that we know of or the first one that has been reported in the media, but I am sure there were others that remained under the radar before this one.
This is the first officially documented case. What it tells me is that there are individuals in Argentina who have likely paid for various transactions like buying cars, food, phones and other things using bitcoin. However, because they do not speak about it, we assume that it has never happened in Argentina. These individuals need to leverage social media platforms like Twitter, Instagram, TikTok, and Facebook to communicate their first of a kind bitcoin transactions. However, they must not sacrifice their security and anonymity for popularity or validation from the public so that they don't get attacked by bad guys. Everything should be don't with the highest level of anonymity just as we can read in the OP where the personal information of the parties involved where nor mentioned.