GR and Narra - I think the crucial point is that the statement refers to 'areas with a surplus of property'. Only 6 words but very crucial.
First - such surplus areas are hardly common, as Gavin notes (they occur more in the areas where previous Tory policy has descimated manufacturing and the workers have 'got on their bikes' to overcrowd the preferred financial centres), and there is no action to make up the housing shortage let alone create a surplus.
Second - the whole government policy is to force rents up to market levels with their stated safeguard that 'housing benefit will take the strain'.
So the outcome of lowering rents is not occuring, and there is no prospect of it doing so.
What is likely, in terms of lower rents, is the further subdivision of buy-to-let homes in order to squeeze more families into ever smaller spaces so that they can just about afford the rent, but the landlord can still increase their margin.