“Skywalker is dead, the Republic, Destroyed. The work of generations is complete. The day of revenge is at hand, the day of the Sith. Send the fleet across all the galaxy, let it burn. The Final Order begins.”
“Yes my lord”
It raises the steaks from “a world they know” to the entire galaxy. It also ties everything in the past two films into a neat knot.
Now Poe’s dialogue makes more sense in response to this. “so Palpatine has been out there all this time, pulling the strings”