My bet: They're probably going to initially go after some actual problem accounts, then once they got the PR out, immediately start using it for bad faith surveillance.
Porn websites should not have to do a parent's job
They would have to either host a metric shit ton of personal IDs on their servers or have direct access to that database. I would absolutely not be willing to entrust my ID to any site that was not a government site.
If you are interested in seeing why this is a bad idea, I'd recommend looking up the KOSA bill (US version of this) and watching arguments against it.
He is the most intelligent business man on the face of the earth, right?