No need for new scalable cities.

Human interactions will develop in the virtual dimension.

Virtual and Augmented Reality will keep you in touch with your friends and get you to your workplace.

You don't go to the store. The Internet of things brings the store to you.

With V/AR you will not only fully access any city around the world but a large set of virtual places and cities limited only by imagination.

There still be transportation and physical proximity like there is still paper books but that wouldn't be the place where the biggest chunk of the economy lies.