From your own quote...
So says right there, the same as Fox said. Zone expansion is not the same as tighter restrictions though. I'd assume it simply means an increased area.
Petrol vehicles that don't meet Euro 4 standards and diesel vehicles that do not meet Euro 6 standards will have to pay a ULEZ daily fee (£12.50 for cars, vans and motorbikes; £100 for buses, coaches and HGVs) to drive in the zone, 24 hours a day, 365 days a year. Approximately petrol cars more than 13 years old in 2019, and diesel cars more than 4 years old in 2019, will not meet the new standards. The total cost, with the congestion charge added (during the times of day it is applicable), for motorists with non-compliant cars will be £24 a day.
The ULEZ will apply to all vehicle types, except black taxis. It is estimated that introducing ULEZ in central London will result in nearly a 50 per cent reduction in road transport NOx emissions in 2020.
So says right there, the same as Fox said. Zone expansion is not the same as tighter restrictions though. I'd assume it simply means an increased area.