From your link:
So, is he arguing that Crown should cancel their contract with Cuomo and then Regnery should offer him a new contract? Because that’s what happened with Hawley’s book deal.
The “rules”, Dumbass Donnie, are that a publisher can choose to seek or terminate a business relationship with any author based on whether they think association with that author will be helpful or harmful to their brand. That’s it. There is no “rule” saying that Regnery has to refuse to publish Hawley’s book because S&S refused to do so, or that Regnery has to be willing to publish Cuomo’s book if Crown is willing to do so. Publishers are entitled to make their own decisions in this matter without reference to your toddler whinings about what you consider “fair” or not.
That said, I personally wouldn’t care at all if Crown decided to drop Cuomo from their author list due to his negative publicity. There are going to be plenty of important informative books about the COVID crisis coming out over the next few years, and I’m not convinced Cuomo’s would be any great loss.