And that establishes a precedent. So, in a future case that is less sensational, the court could order to Apple to unlock that phone as well and Apple would have to comply. Apple doesn't get to pick and choose which court orders it complies with. That goes for court orders in the US, China, Canada, etc...

Apple cannot do the unlock. They're attempting to force Apple write new software that will make it easier to brute force the passcode.

Whether they force Apple to also do the brute force themselves, or the FBI does the brute force, is not really the important part.