He first disclosed to the DOD IG in 2021 and the IC IG in 2022. The full detail of his claims has been available within government for 2 years and there isn't a single sign or tell from gang of 8 members like Schumer or Rubio that they are aware of anything.In fairness to Grusch, he has presented "evidence" in both closed door meetings with Congress and to two Inspectors General. Whether he has presented credible or actionable evidence is another question.
We also know that Grusch associates with Knapp, Stratton, Taylor as there are photos of them together. We know for a fact that 3 of the 4 in that group believe that UFOs encounters are a paranormal event. So what's the likelihood that Grusch's evidence was full of talk about space ghosts and poltergeists that no sensible politician wants to be associated with.