The web site information is unclear as to the extent of the mandatory euthanasia zones as it specifies "some neighborhoods within or near" the cities listed out. I wouldn't put any birds down until it was certain that your exact block/neighborhood is affected. The FAQ section states:
"All birds that test positive for vND are euthanized. There is no cure. If a flock is too close to a positive flock, (next door, sharing a fence line, within the same block or blocks, etc.), it is possible that although birds test negative for vND, they may be euthanized because they have been exposed to the virus. Unfortunately, this is the only way to stop the spread of the disease. In areas where significant numbers of positive cases have been found, birds on entire blocks, or within sections of neighborhoods, may be euthanized to control the spread of disease."
I don't want to hold out false hope, but depending on what's happening immediately around you, maybe your birds will be spared. Also, if they are still young, I might bring them back inside, or at least put there someplace where wild birds can't interact them, until this sorts itself out.
Thinking of you and hoping for the best.