I suppose having the galactic state of affairs be somewhat of a parallel to things in the OT does offer something fittingly parallel for Luke to forsake, especially related to a new call to adventure with his father’s lightsaber.

I can see how TLJ, being written by someone receiving TFA as a complete entity in need of a follow-up, would want to set it up like that. It gives Luke something to rise to and comment on the phenomena of galactic civil war itself, transcending the concrete manifestations of it, just as Luke does so with himself, becoming a legend and departing this mortal coil.