After being announced in the early 2020s, by October 2023 Activision Blizzard was officially in Microsoft's hands. However, the US Federal Trade Commission or FTC wasn't particularly pleased with such a large gaming publisher being owned by Microsoft.
Back in December 2023, the FTC tried to appeal the court's initial decision to let the deal go through. However, recently that appeal was rejected, and now the FTC has decided to let sleeping dogs lie and drop the case entirely.
"Today's decision is a victory for players across the country and for common sense in Washington, D.C. We are grateful to the FTC for today's announcement," wrote Microsoft president Brad Smith (via VGC).
The courts ignored the FTC's appeal essentially due to the body not being able to prove that Activision Blizzard games would be kept from other platforms following the deal's success. We know for example that Nintendo and Sony have deals to keep major titles like Call of Duty on their platforms for years to come.