A question to ponder is this: How will London't financial markets survive Brexit? So far, there hasn't been a mass exit of firms and the real estate market in the city hasn't collapsed. The "just you wait" crowd could be disappointed by the general inertia that accompanies such events, as well the possibility that Theresa May won't be the person negotiating the Brexit terms.
London will still be a haven for rich foreigners to park wealth in the form of real estate. A smart kleptocrat would spread some purchases of residential and commercial real estate around between Vancouver, London, New York, and Miami.
Renzo Piano knows how to design a nice skyscraper.