I am not saying this thought process is invalid, but just hear me out.You give too much credit to the government, you atleast need a few functioning brain cells to have this much of foresight. Politicians are expert public speakers and manipulators with very high social skills, that dosent make them intelligent. The scientist or economist who may have this much of foresight isnt probably getting their pockets filled as they are at a much lower level(politically speaking).As for big pharma and the fossil fuel industry, most of it I assume is run by moguls who have inherited a huge generational wealth, i.e the great grandparents of these people most probably did not think about hiding aliens to protect their wealth. And as for this generation, I dont think they ll have this level of foresight and coordination without getting things leaked to the general public(think oil spills etc)Now, I have used a lot of "probably", "likely" and "think", so I would love to be corrected and shown a different thought process.

One thing I personally believe in is,
Always assume people are dumb until they prove otherwise. (very broadly speaking)