That depends on the law. For example, it's possible that the US could require Meta to verify ages regardless of nationality, so you the EU (for example) would be subject to it.

I'm not saying that's how any of these laws work, I'm merely saying that it's possible. If enough people sidestep the law by using a VPN, I could countries use a heavier hand (e.g. verify everyone or don't do business here).

I will always oppose these types of laws. I set up my WiFi to connect over a VPN to the next state over because my state has ID laws for porn and social media. It's annoying and increases latency a bit (only like 10ms), so I'll oppose them even if I can sidestep them.