I am sorry but Luffy choses the journey not the other way around....he made the choices to do what he wants to do...he made the choice to go to enies lobby, marineford, alabasta, wci, wano....he had other easy choices and paths to take...destiny just guides him based on his will, not the other way around....for example, he took the path of rescuing robin from enies lobby even when it is impossible and robin was "destined" to die if Luffy didn't make that choice....then "destiny" helped Luffy in the form of sea train/gallela workers etc.
Yet everything that is happening is already destined to happen since 800 years ago it seems, not just "the sea train / gallela workers", everything!
In fact, we already saw the prophecy of Luffy destroying Fishman Island together with the Red Line during that arc. Everything seems to be set in stone, and Luffy is just gonna do what needs to be done so that happens, it seems like everything was set up before Luffy was even born. So no, it does contradict One Piece theme of freedom and doing whatever you want, if everything you want to do is already determined you were gonna do. The only solution is if Luffy finds out about it and then rejects it, then that would be a good twist.