I don't think this is a left- or right-wing issue: Australia was one of the first to ban kids from social media, and Australia is not right-wing by any measure. Canada is hardly right-wing, but age verification is bill S-210 in their parliament.

What you're seeing is a coordinated push by transnational interests; Meta's name has come up in discussions of the funding behind this push. At the very lest, verifying age also verifies that a person is real and not a bot, so advertising firms like Meta will benefit from verification. That's not right-wing or left-wing but rather the influence of business over the political, and neither wing of the spectrum is immune to corruption.

There's 2 axes on the political spectrum. Economic and Social axes. Liberal and Conservative is one dimension (Economic) and Authoritarian and Libertarian is another dimension (Social).

In the US both the Democratic Party (Liberal) and Republican Party (Conservatives) are considered Authoritarian on this 2 dimensional graph.

Milei claims to be a Conservative Libertarian so, in theory, he should be opposed to this. We'll see what he actually does.

Milei is a libertarian, and would be very opposed to such a thing.