FAA response to certain parts of JATR . . . .
A very pointedly relevant question! A few suggestions for possible answers:
1) The anticipated NPRM for the AD for modifications (as explained upthread by wrench1) would be an interesting place for FAA to address what it has done about JATR recommendations as well as what it has deferred, rejected or otherwise not acted on. And then the public comments on the NPRM could, at least as a general matter under administrative law, prompt the FAA to modify the AD in more than minor ways. But the JATR recommendations noted by Benjamin's post would have to have been designed into the recertification flight test program already, no? And is it known whether this was done?
2) Relatedly, and also as clarified by wrench1 earlier, the pending JOEB and FSB inputs will yield a report which in turn will be subject to public comment, for administrative purposes. Those groups' reports, and the comments on their work, also could press FAA to address the JATR's recs . . . although again, if the recertification flight test program hasn't already included what JATR recommended, would FAA go back and retest?
3) The FOIA (Freedom of Information Act) lawsuit by the Flyers' Rights group, seeking all the documents provided by Boeing to FAA with regard to recertification, has been plodding along for months. The point of the lawsuit is not mere receipt of documents, though - the explicitly stated purpose of the lawsuit is to obtain those documents so that Flyers' Rights and a kind of "shadow FAA certification experts cadre" it has assembled (which includes famed Capt Sullenberger IIRC) can assess whether FAA has acted properly or not. Which would imply a vehicle to try to intervene via further court action to arrest a flight test and recertification program which has failed to account properly for the JATR's recommendations, and halt the return to service. (I don't speak for the Flyers' Rights group, I'm not involved in their case at all, and this is just an SLF-att'y assessment of what ....*plausibly could* happen.)