If it was nonsense, why did the Inspector General find his allegations "credible and urgent", and forwarded them to Congress, where Grusch and other whistleblowers deposed under oath? And why have several Congressional committees announced that public hearings will be held in the upcoming months?
Let's not make the mistake of thinking that just because evidence has not been made available to us it means there is none. We don't get to learn the most highly classified weaponry in the Pentagon, why would non-human technology be released any more widely? If you want more information to be made public, go write a letter to your elected officials telling them this matters to you.
My understanding is that it referred to his allegations that some programs are being funded without the necessary Congressional oversight.
Either way, the matter of fact is that Congress is addressing these concerns regarding oversight, not the reprisals suffered by this particular person. See the recently proposed regulation by Gallagher.