Have you looked up the definition of the word "banned"?
"to prohibit, forbid, or bar;"
These books are no longer being published; this is a legal freedom that the publisher has. They are no longer sold on Amazon; this is a freedom Amazon has. They are still available somewhere in the US, they are still legal to read, and they are still legal to own. This isn't banning, this is becoming distasteful to the market.
They have simply become less convenient to acquire.
Have you looked up the definition of the word "banned"?
"to prohibit, forbid, or bar;"
These books are no longer being published; this is a legal freedom that the publisher has. They are no longer sold on Amazon; this is a freedom Amazon has. They are still available somewhere in the US, they are still legal to read, and they are still legal to own. This isn't banning, this is becoming distasteful to the market.
They have simply become less convenient to acquire.