Seriously, I doubt it would even take that long. We get used to shit so quickly, and the news cycles have to keep feeding us new things, the only way we’d keep talking about the aliens if they kept doing new and interesting things. I’d be willing to bet a year later there would be some people who straight up forgot about it. “Oh yeah, aliens! Are they gonna, like, visit at some point or just keep exchanging calls with the Whitehouse?”
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.