please stop thinking “expunge this, or expunge that”.
Might as well since the FAA has made it pretty clear what it thinks of expungements. This is from the MedExpress User Guide. Note the last two sentences dealing with reversals on appeal and expunctions. (I am not saying that one or both of those might or might not be successfully challenged while you are facing certificate revocation for giving a false answer.)
"Conviction" means any judgment of guilt based on a jury, court, or military verdict, a plea of guilty, or a plea of nolo contendre/no contest. Examples include, but are not limited to, assault, battery, disorderly conduct, domestic violence, driving under the influence, driving while intoxicated, murder, possession of drugs, public intoxication, reckless driving, etc. If you answer yes, you should report all misdemeanors and felony convictions regardless of the classification of the conviction and regardless of whether the conviction is pending on appeal to another court. List the charge(s) for which you were convicted, the date of the conviction, and the state, federal, military, or foreign court in which you were convicted. If a conviction has been reversed or vacated in a final judgment, state the date of the final judgment and the court that issued the final judgment. If the record of a conviction has been expunged, state the date that the record was expunged and the court that ordered the expunction.