Please remember as with all rumors, they are rumors and never assume they are true.
(Taken from Darnok's post)
Empire will get 4 new kits, new knights, 2 new characters, and a new war alter. The alter is rumored to be a double kit that you can also make a Nuln cannon with. which is a very very big cannon used to protect the city of Nuln. The new Knights are also rumored to be demi-gryph knights, like the one released by forgeworld, shown below.