These are two different legal issues.
1. Could Roger Stone's book be removed from sale because he violated a gag order?
Not automatically. A violation of a court's gag order can expose the person subject to the order to sanctions, including potentially contempt proceedings or changes to conditions of release. But arresting or sanctioning the author would not, by itself, make an already-published book illegal or require bookstores and publishers to withdraw it.
The precise answer would depend on what the court's order actually prohibited and whether publication of particular material was covered by that order. There are also serious First Amendment concerns with a court prohibiting publication, particularly when attempting to restrain a publisher or other third party that is not itself subject to the order.
In Stone's 2019 case, the court's restrictions concerned public statements capable of prejudicing the pending criminal proceeding. Therefore, the important question would be whether the particular publication violated the terms of the court's order—not simply whether Stone had been arrested for some other violation of it.
2. Would writing about crimes violate a "Son of Sam" law?
Writing about one's crimes is not itself a violation of a Son of Sam law. These laws concern whether a criminal can financially profit from publicity surrounding his or her crimes and whether some proceeds can be made available to victims.
There is also an important constitutional qualification. In Simon & Schuster, Inc. v. Members of the New York State Crime Victims Board (1991), the U.S. Supreme Court struck down New York's original Son of Sam law because it imposed a content-based financial burden on speech and was not sufficiently narrowly tailored.
Other federal and state laws designed to prevent criminals from profiting while victims remain uncompensated can operate differently, so simply admitting or discussing criminal conduct in a book does not automatically mean that its author has violated a "Son of Sam Law."
Thus, a gag-order violation could lead to consequences for Stone personally without automatically removing his book from circulation, while Son of Sam-type laws concern profits and victim compensation rather than making the book itself unlawful.
