God has never claimed that only He knows the future. He has created laws according to which we predict future all the time. A meteorologist predicts the weather every day, we can predict the time of arrival of a plane or a train, and many other such things.
The predictions made in Simpsons show can be explained. I am sharing the link below, but the gist is that there are a lot of intelligent people who put their minds together to write these shows. These individuals have a very good grip on a lot of subjects including art, culture, politics, etc. and they predict things on the basis of their knowledge. Out of thousands and thousands of shows, a handful of predictions do come true. There’s really no magic there.
The Simpsons Has Predicted a Lot. Most of It Can Be Explained | New York Times