Politico article contains a link to the letter dated 2 January 2022 replying to the Dec. 31, 2021 letter from Buttigieg and Dickson. Even reading it for speed over accuracy, it's pretty evident that ATT and Verizon had their reply teed up and quite ready to be dispatched.
This volley in the exchange is both longer and more detailed than the government's letter a few days ago.
https://www.politico.com/f/?id=00000...f-fe3e997f0000