It appears that an additional 25 buses have now been ordered (based on numbers) with at least three arriving Christmas week in Halifax.
Go Transit bus numbers 8140 and 8146 wait to be driven away from the Fairview Cove container terminal. A third bus can be seen in the terminal, but in an unphotographable location and its number isn't visible.
The double deckers of this new Enviro 500 series are longer and lower than the pre-2013 models, allowing them to serve more suburban areas in the GTA, along the Highway 407 corridor. With a capacity of 81, they are really coaches, as opposed to transit buses. This new order is also painted in GO's revised darker forest green colour scheme introduced in 2013.