More likely: Ofcom is seeing traditional media dying, so the bureaucrats needed to come up with something to remain relevant and employed.
Ofcom is supposed to be funded by fees charged to the companies that it regulates. There are no hints of social media having to pay them yet, but in the future?
Think of all the work that OSA is creating: age verification companies, regulation compliance consultants, certifications, etc.
Once private companies in the US figure out how much profit they can make off this, they surely will follow..