Metroid Prime 4 as the first installment of a new trilogy?

I don't have anything substantial to prove this idea, mainly just vibes from the last trailer. I think the rivalry between Samus and Sylux will unfold in the span of a trilogy and Samus' adventure on Viewros will be only the beginning. How likely do you think is that Retro Studios and Nintendo made this not as a standalone but already thinking of a trilogy?