The current seeds given to the public the ACF were counting on have very poor survival/growth metrics and they're giving up on that line; big shame as those are the seeds they offered to donors (and thus a way of getting involved as as outsider).
I bought some of those seeds and I just thought I had a black thumb. I planted my surviving seedlings this fall, a month before frost, and I hope they will survive winter..
Our mature American Chestnut tree is well established enough that it dies back some every few decades and recovers. This year I got 50 or so chestnuts out of it. I ate a few, they are great and never seem to get the weevil that the Chinese trees we have do (basically if I don't process the Chinese ones immediately after harvesting in a hot water bath, they will have a grub bore out of them in a week or so).
Been trying to find people outside blight region (somewhere like Michigan/Wisconsin) to plant the American ones so they have a shot. This tree is not a result of any of the ACF's crossbreeding, it's just a survivor that's over 100 years old.