The information doesn’t have to be evidence of aliens existing to be “urgent and credible”, the statement says “The ICIG found Mr. Grusch’s assertion that information was inappropriately concealed from Congress to be urgent and credible in response to the filed disclosure.” which could mean it can just be about the organizational structure of the agencies, for example.
And I wasn’t going to mention it but this is the second time you bring up Snowden, who neither “[dumped] his load” nor “defected to Russia”. He released information to journalists that the US government was illegally spying on its own citizens as well as its allies in a much broader way than anyone outside imagined. He was then stuck at an airport in Russia because the US government revoked his passport during a flight that landed there. He has repeatedly asked for a fair, public trial instead of being put in a dark box at Guantanamo and received no agreement of that from the US government so he’s stayed in one of the only places where he won’t be extradited to a country that intends to make him disappear. Since then, he’s criticized authoritarianism and governmental overreach while living in one of the most brutal dictatorships on earth, which takes more balls than either of us have.