The clue is in the name. The U stands for unidentified, which means you don't know what it is, which does not in turn mean that it's aliens. The only thing those videos proved was that someone's camera recorded something weird. Prove that those weird things were actually aliens and not some obscure sensor glitch or weather phenomenon or a secret government tech demo, then we'll freak out.

I remember watching them and the conversation about them. But that's different than proof and admission that sentient alien life exists. It's one thing to suspect while also having other possible explanations (could be secret tech that we or adversary nations developed, could be sensor errors or optical illusions) and another for the president to be like "I want you to meet ambassador Xlurg"