I received a similar answer with SquareHan, but probably even more clearly stated:
"American Airlines has updated the reward options and they have decided that some of the airlines has been removed. I apologize for the inconvenience."
I signed up through AA, twelve years ago. Strange that they would update the redemption options so drastically after all this time, but it is what it is.
Unfortunately, things change. I still see UA in one of the family accounts and AA in the other. Not sure about the sign up sources, but Hertz points are my preferred redemption option given that I rent apx 7 weeks of Hertz cars every year.