It's not strange at all. If the AP's sources just disappeared, the word would be out to any future sources/marks that the AP gives up sources...but if the big bad government did this rare, but effective overreach...the spooks can still terminate the leak and the AP has plausible denial.
The CIA wants to maintain the AP's ability to lure in more leaks in the future.
The CIA wants to maintain the AP's ability to lure in more leaks in the future.