How does that make any sense? How is the license for a piece of software relevant to verifying age? If I make a site that is objectively harmful to minors, I can just make it open-source and I’m exempt? Or, if I make a completely innocuous site that doesn’t actually do anything but is closed source, I would have to comply?

But really, nothing should be doing strong identity verification outside of stuff like government (e.g. passports), or anything that commonly exploits identity for crime (e.g. major financial operations).