The commission made a statement, saying that Activision Blizzard "would continue to face several strong, effective competitors, such as Electronic Arts, and the game console manufacturers, such as Sony, Nintendo and Microsoft." There were some concerns that the company could have an unfair advantage in licensing music for games because Vivendi owns Universal Music Group, but they were set aside because "competing game publishers would continue to have access to a sufficiently large portfolio of music rights from alternative suppliers."
The lesson: Activision Blizzard is officially not a monopoly, thanks to EA. We could go into extreme detail weighing the pluses and negatives of the decision, but we've analyzed this merger plenty enough already. At some point, you just have to decide to sit back and see what happens.