For HSR Act notified mergers, parties may request early termination (ET) of the initial waiting period. If granted, the ET decision is published. https://www.ftc.gov/enforcement/premerger-notification-program/early-termination-notices. Other than notified mergers for which ET is granted, the DOJ generally only publishes information about mergers if the merger is subject to challenge or consent order.  Under the Antitrust Procedures and Penalties Act, a proposal for a consent judgment submitted by the United States must be filed with the district court before which such proceeding is pending, and published for comments in the Federal Register at least 60 days prior to the effective date.  See, https://www.law.cornell.edu/uscode/text/15/16.