https://www.techdirt.com/articles/20191110/19392843359/fbi-asks-congress-to-permanently-reauthorize-phone-record-collection-nsa-voluntarily-shut-down.shtml

Earlier this year, the NSA -- after a few months of hedging -- finally mothballed its phone record collection program. The modified phone metadata collection had posed problems for the NSA since its remodeling with the enactment of the USA Freedom Act, which forced the NSA to ask telcos for specific records, rather than just demanding they hand over everything on a rolling 90-day basis.

Whatever benefits this program provided to the NSA was apparently outweighed by the technical problems it created. After hinting at its impending death on a podcast of all things, the NSA made it (sort of) official in May, saying it didn't see any reason to move forward with the collection, not after it had already been unofficially shut down for several months by that point.