Historically, Emperor Taizong's attempt to kill Wu Meiniang was stopped by an expert. What's the mystery behind it?

In the twenty-second year of Zhenguan, Taibai Star appeared different images, and he urgently recruited a surname to make Li. After calculation, Li told him that within 30 years, this woman named Wu would replace him in charge of Li's world. I was going to kill all the women surnamed Wu, but Li dissuaded him from changing his established policy.