I don't think they necessarily had to. There's always been a stigma involved with this stuff that it took care of itself for the most part. A stigma likely created by them in the first place.
According to this new information coming out from Grusch, most of these "retrievals" are done by private entities and not necessarily the government. That's where all this new proposed legislation seemingly stems from; private entities basically bogarting all this absurd technology and hiding it from everyone else (including most of the government, though there are supposedly factions/individuals that are privy to the information and hiding it themselves). Government officials knowing about this and not sharing that knowledge is a criminal offense, so of course they wouldn't want that information getting out there.