I had heard that Michael Salinger was concentrating on issuing his father's published works as ebooks before he published anything new.
I believe in 2019 The Catcher in the Rye, Nine Stories, Franny and Zooey, Raise High the Roof Beam, Carpenters, and Seymour An Introduction were all made available in e format.
I am not aware of any other published material for Michael to be working on, so the question is, what the heck is Michael doing? I'm hoping to read something new by his father before I die.