I think this 20 year policy has only 2 purposes:
1) appease the public and show them that they're "doing something", no matter how useless that thing is
2) possibly blackmail these companies to give the government their data more easily next time they request it - or else.
It's pretty obvious the government doesn't like to tangle with big companies unless its necessary. Large corporate legal teams can drag out a fight for several years, earning the ire of state senators voting constituents, and having a negative effect on their re-election possibilities.
What is curious to me, is this seems like small fish compared to years of "unlimited" and "free" being abused in marketing.
Also note that there is as difference between regulatory actions and enforcement actions. The later are inherently smaller in scope but necessary for the former to be meaningful.
"Any company that makes misrepresentations to consumers about its privacy and security practices risks F.T.C. action.”
But, yes, users can be easily confused, and they (intentionally?) got more downloads / users because people mistakenly believed that the images were 100% deleted.
For the HN/Techie audience, we of course never believe anything digitally transmitted to a recipient can be 100% deleted by the sender. Nothing will ever prevent brute force things like "having a camera over my shoulder, recording my screens".