One thing to consider is that once a bird leaves your property, you have no control over what happens to it.
Also keep in mind that some people lie. So you can rarely be sure what they intend to do.
Many "animal sanctuaries" are simply animal hoarders, and the conditions are not good for the animals. Over crowding, not enough money for food, let alone vet bills.
Something else to keep in mind. Many people will take anything that is free, whether they need it or not, whether they know how to take care of it or not, whether they have facilities to keep it or not. They will even take things they don't even want just because they are free.
If you intend to give birds away, either do not care what happens to them or be exceedingly careful about to whom you give them.
My good show birds that people pay good money for, I don't worry about them so much. I speak to the people to see if they know what they are doing. But generally, people do take better care of things that they want badly enough to pay money for. Old birds that are no longer useful, I would rather butcher them humanely than to throw them out into the cold cruel world where they are going to take their chances on the care they will get.
Even though I no longer want them myself, I don't want them starved or used to train pitbulls to kill. I know that if they are no longer useful to me, they are not going to be of much use to anyone else, either. Which makes it dangerous for the birds to be put out there at the mercy of others. If they go into my own freezer, I know that they haven't been starved or abused or used in cock fighting to train the "warriors" how to kill. I know they've been well cared for until the last second and I know they have been humanely killed and not frightened.