The flaws with a line city are just so glaringly obvious:
1.Failure of the transport links at one point, pod railways or whatever else they use along the line could effectively be knocked out for the whole city due to failures in one small section. Even with several in parallel they'd all run close together so localised damage of some form could easily affect all parallel lines. With the lack of cars, and as a linear shape means things are much further apart than if distributed across a 2D plane means most places people need to travel between will be outside walking radius, the city will be extraordinarily dependent on that all-too-easily-single-point-failed linear public transport infrastructure.
2.Fires, it would be all to easy for fire to spread in that sort of dense 3D (at the small scale) city, outward from the originating point to encompass a block slice of the line, and then later spreading along the line's length, and a lot of the fire would be inaccessible to firefighters who would only be able to reach the ends of it, with all the burning mass at the core able to keep burning and reignite anything at the ends which was temporarily extinguished.
3.Surveillance, all too easy to monitor every movement of every person when all movements are to be along the city. And being freshly built they'd have the opportunity to embed cameras and microhpones everywhere, including undoubtedly hidden ones in the sections assigned as "homes". No doubt plenty of the line city's backers are the kind of scum who see this as a benefit not a flaw.
Not to mention 4.Cost, any short section of this will cost as a much as a skyscraper, you could build far more city, for far more people and containing far more space for economic activity, by putting this colossal amount of money in to a normal city layout.
P.S. are we really sure that the drone footage isn't just them building a railway embankment or airport runway as part of a more conventional city building programme? Particularly on account of point 4, the idea people would even attempt to build that line city is hard to believe.