My wife and I have had and been part of the life of 13 foster kids in almost 40 years of marriage.
We also have a spec. needs adoptive son who we got when he was 14 mo. old he is 35 now and still lives with us.
The one thing that I can say about a rehomed parrot is that it`s no differant than a child in need.
No mater how bad the old home was they know what they had and want to stay there because that is all that they know and what to expect.
Evean when the new home has love they wait for the boom to fall and go back to what they had before.
There are 20 nonhuman members in our family and over half are rehome.
Time and kindness is what makes the differance in the outcome and to know that they don`t have to go back to what they had.
In the new year may all pets of all kinds find a place that is safe and comfortable and they don`t have to go back.