No one claimed the AI "is so smart" - it's another tool in their kit. The article clearly conveys that the potential is a useful way to augment human-led research by providing a way of quickly processing large datasets i.e. the 20k signals are filtering down 150 terabytes of data which is much more manageable for human analysis. It's not like we have definitive parameters of what constitutes an "alien signal," so we can't exactly create an absolute model for detecting such telemetry. Instead the goal of the article is to simply demonstrate exciting new ways to leverage machine learning methods in different contexts