Why now? Because in the past 2-3 years it has been made abundantly clear that:
(a) Social media operators choose to do nothing at all against coordinated influencing operations, unless the influencing goes against the interests of very specific countries and groups.
(b) US government most likely has unfettered access to social media data. As if this isn't bad enough, they will probably give them out to Palantir for "data integration" and under uncertain terms.
Those things were pretty clear well before 2-3 years.
Social media is seen as a driver for people having opinions deemed a threat to the status quo. Western governments have been fighting a long battle to use these tools to control domestic influence and at times have probably thought they were winning, but recently things seem to be turn a bit.
"Think of the children" is obviously the oldest and most pathetic trick in their playbook. We know it's a bald faced lie because data and studies on social media harms on children has been coming out for well over a decade by now, and not a finger was lifted for years. So we know that is not the reason, and we know they are lying about the reason. Therefore we know the real reason is seen as unpopular with the electorate. And curbing foreign (including US government) influence and access to data is not unpopular anywhere.
(a) Social media operators choose to do nothing at all against coordinated influencing operations, unless the influencing goes against the interests of very specific countries and groups.
(b) US government most likely has unfettered access to social media data. As if this isn't bad enough, they will probably give them out to Palantir for "data integration" and under uncertain terms.