Beyond that, though, there were no major updates on MIB23‘s development. Jonah Hill said in August 2016 that he doubted the movie would get made because the point of the Jump Street movies was to make fun of sequels, remakes and reboots, and by crossing over with Men in Black, the property would become the very thing it was mocking. More than two years later, Hill’s prediction has come true, as there just wasn’t any way to effectively bring these properties together.
Article source: https://www.cinemablend.com/news/2464777/the-men-in-black-and-jump-street-crossover-is-no-longer-happening