Should London have a different name in any modern references?

May sound stupid but I've often wondered how in fiction writers will invent/change American cities (Racoon City, Gotham etc) yet keep the names of all other nations cities, Unless they just invent a country (Val Verdi).

Think 'Thames City' is a good enough parody name. Makes as much sense as 'Liberty City'(New York) or 'Vice City' (Miami).

Maybe they can have references to up norf Newfort and Weegie City.