You have a point, but a major reason that the examples you cited above were kept secret was because knowledge about them was compartmentalized. As knowledge leaks, so does the possibility of whistleblowers. It’s an unstable equilibrium. My argument (which admittedly is based on an anecdata about how undisciplined large tech corporations are) is that it’s uniquely hard to keep secrets in modern tech companies because by design, knowledge is not compartmentalized. Modern large tech companies have replaced fiefdoms of knowledge with fiefdoms of operational expertise, if that makes sense.

Anyway, there have been hundreds, perhaps thousands of whistleblowers in the past and the examples you picked I think are representative of the upper bound, rather than the lower bound of the secret keeping capacity of organizations.