A. The U.S. relented. The UK was never a massive player in this deal, they were just one of the first to loudly dissent. While the U.S. was blocking the deal, they were able to easily point to the FTC and sit on their hands. They caved pretty soon after.

B. Microsoft made some promises. Ubisoft is going to get game streaming rights, which means if Microsoft wants to make any of their games available on Game Pass, Ubisoft has to agree and Microsoft will have to pay Ubi for the privilege.