I think this is kinda normal. To get an appeal at a higher court, you first you need tell the current one that you find their decision was poopoo.Mergers bad
But this is extremely funny
The US is also legally in a very weird place where companies can accrue as much marketshare as they want really, as long as you cannot convincingly argue that they are forcing monopolistic rents on consumers. So even if the deal gave Microsoft a huge advantage over Sony (which is dubious) that would not be enough. Maybe a hundred years ago, sure, but in a post-Reagan USA. And Microsoft is still at the point where they giving away Gamepass for cheap (you can get pretty much all their AAA games there, on release, for like 10$ a month?) so who in their mind can argue they are extracting monopolistic rents, so money they couldn't force people to pay if they weren't a monopoly.