As I see it, the paper, a private business, has the right to hire whoever it chooses. Unless they circulate the list throughout the industry in an attempt to get all newspapers to refuse to hire these writers, in which case they would be conducting a public vendetta.
I see no indication that such is the case thus far.
If the paper were refusing advertising dollars from, say, some major polluter or gun manufacturer, I have no doubt that some members of the National Writers Union would applaud the decision.
Why should the paper have the right to refuse an ad but not the right to refuse to hire a writer?
I repeat, as long as the list is not being sent out industry-wide, it can hardly be compared to the blacklists of the McCarthy era.
While I am not personally in favor of such lists, I recognize the companys right to promulgate one internally.

troll