Many might disagree with me, but I think one of the reasons is that they decided to split the movie into two parts, so they can’t use all the most "hyped" moments of Michael’s life at once. According to rumors, Smooth Criminal will only appear in the second part. But Michael’s character from that video is one of the most recognizable and iconic in his entire career, and they aren't using it because it won't be in this film. The same goes for The Way You Make Me Feel, Black or White, They Don't Care About Us, and so on... They wanted to generate hype for the movie using Thriller, the best-selling album ever, but in the end, they just limited themselves! What an irony