No.
Yes, it only shows those apparently.
As indicated, all balance subject to change - this building in particular. Not entirely sure I agree that it's useless though. Might be niche, but one can hold up some pretty huge armies through a mountain gate with earthworks; yielding an effective combat width of 9 or 10 if memory serves. They can only be constructed in fort provinces; meaning unless your fort has fallen, you'll always be treated as the defender.
There have been additional changes to population capacity % modifiers which render this pretty hard to achieve. Notably, technology itself provides reduced population capacity %, and to receive the invention modifiers to popcap, you have to invest a considerable quantity of innovations to unlock the majority that were pretty much de facto available before. Whatever you're spending in these results in points you aren't spending elsewhere.
Without innovations, I've been hard pressed to get a metropolis above 300 pops (while cheating thoroughly, and building only aqueducts) - I don't see much value in entirely preventing this playstyle for those that wish to engage in it - the important thing is that engaging in it is now something you actively build towards, at the expense of other things.
EDIT: Another honorable mention is perhaps that the various bonuses to output for simply existing in a capital region/province/city have been hugely reduced. Civilization is key to output now - stacking population in somewhere that magically results in higher output is no longer nearly as viable.
in terms of population and very simple, and just to reduce food expenditure, a very large population in a city will need absurdly much food. this can also be understood for the time of year. this would make it possible to create a large city, but there would have to be many, many more fields with componeses to feed it.