More than likely we’ll see the Bumblebee movie open with references to things that we saw in The Last Knight becoming more important.
What does seem clear is that while there will be items in the script that are there for that specific purpose, Transformers: The Last Knight is not being specifically designed to build toward the Bumblebee movie.
The film probably won’t end with Bumblebee going off on his own to follow a new mission.
The producer certainly dances around his answer, and he doesn’t want to be too specific about what we’ll see that will lead into the next film.