The judge considers it reasonable because if the market is as the FTC defines it and if Call of Duty is actually an essential input for a competitor in the "high-performance gaming console" space, then those commitments from Microsoft give Sony ten years to innovate and come up with a replacement for CoD. It makes a lot more sense if you read the whole judgement, Judge Corley is basically saying "Most of what the FTC is asserting is questionable, but even if we assume that their assertions are correct, the argument to temporarily prevent & potentially permanently ban the deal to prevent harm there is little evidence for is not strong enough to harm Microsoft and Activision in this way". There's other stuff that had some impact as well, like how the FTC knew the deals deadline (six days from now) more than a year ago, but only chose to bring the PI motion recently, giving Microsoft barely any time to prepare (and making the federal judge in this case have to work some unusual hours, including the entire weekend, because it's now so time critical). Basically, a lot more went into this decision than just the ten year agreements.