Even though Jamie Gorelick left the Pentagon in 1997, and Able Danger was dismantled in 2000, she would have maintained contact with Cohen, Shelton, and Pentagon lawyers. It's not outrageous to think she might even have informally, been asked her opinion on the legality of Able Danger.
There's no doubt in my mind, Gorelick's first instinct would have been to protect the Clinton administration from allegations the Pentagon had a secret project going, that was violating the rights of American citizens.
PING- mark for possible Wednesday news.
My take is a little different than yours. I believe that the "Gerolick Wall" was put in place so the DOJ could not garner any information that the DOD had gleaned as to Clintoons campaign financing scandals. The fact that the DOD, which had made the link between Atta (and other perps?) and AQ, was forbidden to give this info to the DOJ was an unintended consequence. IOW, the means used to cover up Chinagate, Riady, etc. also (inadvertantly) covered up the Atta-AQ link and that he was in this country.