By what possible mechanism would any government anywhere control what literally hundreds of thousands of astronomers, amateur and professional observe every night. The idea that intelligent extraterrestrial visitors would automatically seek only government or military officials to whom to make their presence known is laughable.
Millions of people around the world are contactees.
Some of them tell their stories here:
https://podbay.fm/p/aliens-and-artists
Start with the oldest podcast first if you are interested:
https://podbay.fm/p/aliens-and-artists/e/1591313548
Their presence is well known outside of the circles you mentioned. The government merely discredits all who report any sort of observation or encounter. The process of discrediting them is simple and 100% reliable.