If this is true (huge gigantic "if"), then all information on this topic should be immediately declassified. It is unacceptable to keep the biggest discovery in the history of the human race from the public. There is no justification for it.
Believing so suggests there's a purpose to deliberately wasting everyone's time in such a hearing.
Or a simpler answer, Grusch is plain lying. But somehow, the stakes seem pretty high for him to do so here, unless he's confident of the whistleblower book money he could someday make off of this.