It's an interesting claim, but it appears to just baldly assert that the frequency is an illusion. It sounds perfectly plausible to me that something should start cropping up just after you learn about it. For example I started thinking about LLMs not so long ago and then I just started seeing papers about them everywhere. Is that a frequency illusion, or did I just learn about an interesting new technology at a time when lots of people had things to say about it?
Well... I believe that the illusion is a real thing, but a lot of people started talked about it also may be a real thing, and they could happen at the same time. But there is one more piece of the puzzle: probability to learn something raises when people start talking about it. And when it happens to someone there is one more person to talk about it, so it is a chain reaction. So if you learned something recently on Internet, and now you see people talking about it everywhere, then it is probable that the most of people talking are like you, who just learned about the thing recently.
Probably Baader–Meinhof
https://en.wikipedia.org/wiki/Frequency_illusion