If it turns out that the American government managed to hide the existence for aliens and then randomly just told everyone because somebody forced them to that will be amazing.
If they're prepared to talk about it that almost certainly means that they're not aliens.
The US military can more or less just do whatever they want they could totally ignore demands to release information, they could just say oh that was just a classified aircraft test our pilots weren't told about because it's above their pay grade, and we cannot release this information for national security reasons.