The article essentially summarises how many games are now moving towards using real life cities as opposed to realistic false ones. They seem to think Rockstar games has "more than probably" situated the next GTA in London, England.
There is no fact that Rockstar Games have done this, it is pure speculation. We currently have no official word from Rockstar on the location of the next game, and another thing, why would they shrink down the game from 3 cities in an entire state to the comparatively deminuitive London?
First proof of theory is the fact that Rockstar Games has, more than probably - placed the next installation of Grand Theft Auto franchise in the capital of Blightyland.
So far all the sites speculating on the next installment of Grand Theft Auto have based their article around unsubstantiated opinions and until we have an official statement from a Rockstar representitive it would be wise not to believe anything you read at this point, rest assured when the setting is revealed you'll know about it from us.