That prediction is a big word honestly. I think those tools can notice the patterns before ordinary people do, but getting the exact viral content has some elements of luck inside. I have seen one simple video that nobody rate suddenly it blow up everywhere, while another one that looked perfect just disappear into the thin air. The internet do not always follow logic as people think. Even now, one random gist can trend because one celebrity commented or somebody turned it into one funny meme overnight. AI can actually show what people are talking about, but it can't control how humans react.