Following the UK regulator's belief in late March that Microsoft wasn't buying the Call of Duty publisher to make its shooter exclusive, Sony's thoughts on the decision was made public. In that writeup originally published on March 24, the PlayStation maker said the reversal was "surprising, unprecedented, and irrational."
Previously, the CMA had started investigating Microsoft's acquisition of Activision Blizzard to determine if it would be harmful to the game industry and its customers. In that time, Sony has made it quite clear that it wants that merger to not go through, lest it lose Call of Duty, one of its biggest third-party revenue sources.
While the CMA found last month that keeping Call of Duty locked to Xbox would be a financially bad move, Sony shot back by saying the regulator used flawed data. Those findings also reportedly fail to include "the “strategic value to Microsoft of expanding Game Pass."
Sony's argued that the CMA had a "significant body of evidence" confirming Microsoft would withhold Activision Blizzard franchises from competition. Further, the CMA's new "diametrically opposed approach" is based "almost exclusively on a single economic model on which it places ‘significantly more weight’ than other available evidence."
"To reach a robust decision," concluded Sony, "the CMA should revisit its analysis of Microsoft’s incentives and partial foreclosure, correcting for the errors identified in this paper."
Sony continues to fight hard against Microsoft's merger
Keeping Activision Blizzard out of Microsoft's hands is so strong that Sony reportedly told people in Brussels a parity offer for Call of Duty was off the table. For reference, this was after Microsoft had already offered a 10-year plan for parity to both Nintendo and Steam, and gave Sony a similar deal if the merger went through.
A decision on the Microsoft-Activision Blizzard merger is expected by the CMA on April 26. Before then, Sony will either accept that the deal may be going through or find another way to argue against it.
For the complete timeline of the merger and Sony's involvement in it, Game Developer has created a rundown going through all the significant beats.