If he's a libertarian, he has a strange way of showing it: https://opinion.infobae.com/javier-milei/2013/08/03/el-retiro-de-bernanke-y-el-futuro-de-los-emergentes/

Yes, that's a post from 10 years ago, but he was 42 when he wrote that. By about 25, your perspective is mostly fixed, and definitely so by 42. No libertarian who takes Austrian economics seriously would look at Ben Bernanke as any sort of hero (in the article he claims that Bernanke saved the American economy from a depression).

I predict that, if elected, Milei will do little, if any, of the things he has promised. He'll come up with excuses (e.g. blaming the other political parties and bureaucrats for hampering his efforts). In the end, libertarians will get a bad name as a result of Milei enacting pseudo-libertarian policies.