The FAA will argue the Civil Suits are underway and have not been decided thus have no bearing on the matter unless and until all the evidence is heard, argued, and a Decision is made by the Judge or Judge/Jury.....then there will be Appeals...and again the FAA will point to an on-going Legal Process and refuse to act until the matter is settled in Court once and for all.
A separate but related issue....As an Insurance Company providing coverage for an Operator of 225's....how do you countenance the banning of flight by the two Authorities and the approval for flight by other Authorities?
As an Operator.....if you return an aircraft to service...comply with every single additional requirement....and another Fatal Event occurs due to the MGB failing in a similar fashion....then what?
This is not a far fetched question.....remember the 787 Electrical Fires....the 737 Rudder Hard Overs....the DC-10's Cargo Doors.....and several other air worthiness issues that have had similar impacts on the Aviation Industry?
We have to recall....the cause of the latest crash has not been determined with certainty by the Norwegian Accident Investigation.