I use Pop!_OS, and I’ve become aware that they may be forced to put up age verification. I haven’t updated since. Have they implemented it yet? I’d expect to find uproar if they did, but I want to make sure.
Regardless of the age verification issue it is still not safe to not update your OS. 
I don’t want to do it if I’m going to be forced to upload my ID.
You can remove it yourself, Linux doesnt stop you from deleting anything. That’s why this entire identity verification thing is so stupid. It cannot functionality work at the scale they want.
Edit: The things that probably won’t work are the websites and services that require some verification related API. But besides that, you own your device, if you are going as far to even use Linux in the first place, you are already in a great spot.
Then you maintain (some) element of your privacy but forego your security. If you forego your security, in turn your privacy goes out the window and you will have more things to worry about than your ID.
I understand the predicament and frustration but not updating any OS for whatever reason seems like a backwards step.
At this point why not switch?
I read somewhere that Pop!_OS has improved power management, which is helpful if true, because this laptop runs on a coin battery.
system76 are one of the companies so far that have contested age verification
At the moment it looks like age verification is not yet implemented in Pop!_OS. From what I can tell, System76 may only need to comply with Colorado law which should only require self-reported age attestation if passed. The worst thing you could do for your privacy and security is remain on an outdated OS. If you’re worried, I’d go ask for clarification on exactly what is being implemented and when on the Pop!_OS Chat.
Or if you’re extremely worried about this, you’ll have to switch to a distro which explicitly claims they won’t comply with such laws. According to Lunduke’s findings none of them are endorsed by Privacy Guides. But among them EndeavourOS might be the most secure (depending on configuration) and ZorinOS would be the easiest to use.
IIRC System76 CEO got someone to make/made a FOSS carve out in the Colorado law