Possibility 1: Project Stargazer with assistance from Yutani Industries has successfully cloned Dutch into multiple yet increasingly poor resolution copies, ala Multiplicity.
Possibility 2: Using multidimensional Yautja tech a collection of Dutch iterations have been gathered from multiple realities each with their own unique cultural quirks, ala the Council of Dutchs'
Possibility 3: The Schaefer Boys are back in town, Dutch is joined by his brother John from New York and their other two quadruplet siblings, Kimble and Quaid.
Possibility 4: Cybernetic Pred tech has finally been cracked allowing for the creation of unstoppable killing machines in the form of robotic endoskeletons surrounded by living organic tissue, created in the likeness of you know who.