No, it does not. We had 5 games in the series with pretty much cities working the same. There is no reason not to keep the new city building system (the best feature of civ 6) in 7, with some updates for example on how builders and repair work.
Personally I would get rid of charges, and instead make improvements cost money. I would unify builders, engineers, archeologists and naturalists in the same unit, make repairs fully automated (not requiring moving builders, but instead costing money and time to repair, and having negative effects in the meanwhile), et voila.
I would redesign WC (resolutions acting as resolutions and affecting gameplay, and being able to propose them); completely change religion (removing religious units from the game, but instead make religion work with trade, diplomacy and ideology systems); abandon the card like policy interface; and throw away the philosophy of adding modifiers, to use game systems that change how the game work in more meaningful ways (not all bonus need to be abandoned, but the philosophy of everything being bonus).
I would also redesign diplomacy (integrating grievances, envoys, favor and current diplomatic penalties in one single system); make a working AI designing it from the beggining with the full scope of the game in mind; add meaningful spy missions; add world wars to diplomacy options; implement things such as blockades, or allow closing sea/air and civil borders as separate options. I would also rework or remove agendas, and governors (allowing for true city specialization that allows tall play); and I would bring back vassal systems.
I would also remove the eurekas (so there is not a best way to progress technology, but instead choice), and redesign ages completely replacing the "points" and making dark ages a negative thing.
I would also add a health system and make the map truly dynamic so global warming can expand the dessert or change the land tiles; redesign how disasters and flooding work; and of course add earthquakes and tsunamies.
Also I would change the visual style, since lets addmit it, a new game needs to feel and look new to sell. So I would redesign leaders, units and the map to a more realistic tone. Not because I dislike the look of Civ 6, but because 7 would need a new direction to go.
Dont you think that would make more than enough to justify a new game? Cause 6 games in, there is no need to reinvent the wheel in every game, in fact no game has done it in the past.