This is incorrect. Now that the book has won a prestigious prize, normal publishers will likely offer to publish the book the normal way, and so these bookstores will be able to stock the book in the normal way.
If the author's assertion is true, and this novel, unlike his others, was passed over due to antisemitism, then those publishers likely still won't publish.
Additionally, if the author believes that, why should he give them a cut now?
The book was about the experience of jews, not Israel.
If someone's anti-Israel attitude results in them discarding the experiences of people who are merely jewish, then there isn't much difference between that and being antisemitic.
It hasn't won anything yet, it's only listed, the prize winner will be announced next month. Whether or not it will find a publisher on short notice is dubious, there's likely still editing work to do to bring to the level acceptable by many publishers. It might find a distributor though.
