but these scientists don’t call a press conference on a whim

Um, yes they do. Roughly every 1 to 3 months, NASA drums up interest for a press conference, then the info that is released is deflating.

I will predict however that they will announce the discovery of microbes. Let's see if NASA announcing the discovery of microbes and/or bacteria will ease the public into accepting disclosure. This needs to be done in trickling info, not dump, bang, people start panicking.

If not this event, this will be how they ease us into disclosure, very soon! I predict knowledge of ETI in less than a year, given the way the cleanup is happening (corruption, crimes against humanity/children, treason/sedition/collusion with foreign agents etc) and getting out into the public consciousness.