"How is the airport going to react to this significant reduction in their accessibility. The reduction in width along The Embankment and through the City of London to just one lane is part of the permanent scheme; it's not going to go away"
Perhaps the airport owners will encourage an even higher proportion of travellers to use the DLR? The (democratically elected) Mayor has decreed that road space should be reallocated to make cycling safer in London, so businesses will need to adjust accordingly. In fact, many major employers and NHS trusts have publicly backed this development.
The reduction of road capacity at certain points doesn't really affect the competitive position of LCY. After all, those sitting in traffic headed for LHR will also sit a bit longer.