Apple can see what was done on the iCloud AppleID account, which is used to access and purchase apps. They can see when it was changed. That does not mean they can see any personal data that is stored in the iCloud under that AppleID, but they DO have information on that account.
Do you throw out everything you know when you are negotiating with someone, especially something negative, who you want to remain friends with? Apple certainly did not also mention that they had told the FBI four methods of getting what they wanted and the FBI apparently wasn't interested in those approaches. It seems they wanted only the universal backdoor approach of turning off the lockout.
Where is this information available? If this is correct, I may have to reevaluate my thinking.