Seriously, the city is so big and detailed that I feel like Cyberpunk 2077 only scratched the surface of it. Night City is the heart of Cyberpunk and moving to a whole new location would be a huge bummer to me.
Ideally it would take place maybe 10 years after 2077 and maybe another bomb went off or something and turned a big chunk of downtown into a wasteland and now Pacifica/Dogtown is the new hot area.
Supplement this by making part of the story take place on the moon and/or the Crystal Palace and allowing you to travel back and forth like in Witcher 3 and I think that will feel plenty fresh for a whole new game + a couple of expansions.
I'd be very disappointed if they don't. But I have faith that they will stay close to the source and remain in Night City for at least the main storyline.
Honestly I kind of hope there will be DLCs with completely different characters and smaller stories to play, though I kinda doubt that'll happen. Would be interesting though.