It's unusual that yours ignore greens & soaked seed if they have dry seed all the time. In my experience birds will take green feed, egg mix and green grasses & soaked/ sprouted seed whenever they are offered regardless of if there is dry seed available.
Give the birds time to settle in. The new birds have been chased around an aviary, caught and put into a box or transport cage, driven all over the place in a car, and then put into a new aviary with strange birds. They need time to settle in, meet the original inhabitants, learn about their new home & surroundings, and recover from the stress they just went through.
If your aviary does not have any plants in, try adding some tree branches or live plants. Most native trees and plants are fine but do not use anything that produces a white sap if you break leaves or branches. And avoid commonly known poisonous plants like oleanda and angels trumpet.
Wattles, eucalypts, banksia, bottlebrush, grevillia & sheoaks are all fine for birds.
Make sure there are lots of nests around the aviary. And have a few different types of nests as well as nesting materials. Keep nests under shelter and have them all the same height and well spaced out. If you bought the birds from a breeder, maybe email or phone them and find out what sort of nests they used for the birds.
Feed them well and monitor for any signs of disease, fluffed up, running nose, watery eyes, poop on feathers around their bum, wheezing or gasping after flying about or just sitting there.
If the birds are healthy and in good condition, and free of diseases and parasites, and they are not stressed out over the next month, they should start to show signs of nesting soon. But don't expect it immediately. Would you move house and then start a family on the day you just moved in?
I assume they have clean water, mineral grit and cuttlefish all the time. And make sure there are no cats or dogs hanging around the aviary.
You can grow your own green grass seeds in pots and feed them to the birds.