Not sure how it works at the federal level, but in Illinois here we have the Local Records Act, which requires that retention policies be created for all documents/records.
When I FOIA'd for all of the retention policies they initially told me that my request was too difficult, because they were all digital files -- but he was going on vacation the next day so he told me to expect an unduly burdensome denial. I got it the next day from whoever took over.
Anywho -- Most of the retention policies are older than me. That, and the question of whether third party data that's shared with a gov agency should fall under a retention policy or not.. is clearly an open ended question. Edit: found it: https://www.muckrock.com/foi/illinois-168/retention-policies....
Also at one point had to FOIA-sue the White House OMB for their email metadata when they said that they don't routinely use powershell. But they were sued years before where the nearly identical question came up, where they showed that powershell was used. And that's for data that they're legally required to collect for NARA archiving.
Point being -- lol it's a shit show.