Can't give you guys the right answer here.
I can only point to a possible pattern. Mainly, with respect the head of FTC :
https://www.newyorker.com/magazine/2021/12/06/lina-khans-battle-to-rein-in-big-tech
Her move is basically litigate instead of negotiate. And so, respectfully, she makes a solid point that a lot fo these big tech companies buy up shit way too much, in fact in general, and consumers don't have choices at all really, so she's just going to block everything. And it's entirely possible that MS and ABK knew this would happen, and they have been out their publicly going this thing, because they knew they'd be blocked and the counter arguments would be bogus, so get out there early and present your story before the FTC presents its story. _maybe_. They gave up many concessions to not be blocked, but they were blocked anyway. Sony only needed to be enough of a catalyst to ensure that regulators went down this route, they don't really need to do more than that really, the FTC would have made their own arguments, but Sony provided some for them, so that's what they went with it appears. There were some definite fabrications of things, fabrication of market segments, we don't have a high performance and low performance console market. etc etc.
From what I understand the FTC has their own system of administration process internally that does not require the federal court. The FTC pushes that date out as far as possible to gather evidence to win the case to block the merger in front of court. They will likely lose this court because if I understand it, FTC owns this one. If MS loses that case, they can appeal to move the case moves to federal court. , if MS wins the federal court they are free to merge. MS previously had the date to close ABK by June, from what I recall reading, it's now removed all dates on when it thinks this will close.