I think there are important distinctions to be made between accountability and censorship.

The case of changing the forward for your book is very easy to make and quite morally practical. You are rightly concerned that people might not only take offense but feel unable to purchase a book about spirituality endorsed by someone known to be abusive toward women.

As to his own books, that's something for retailers and his publishing house to be concerned about, but the moral issues become less clear. Ultimately, they are going to make business decisions.

If he wrote books about physics as a well regarded expert, his publishers might not feel the need to stop selling his books. If they did, many people might agree that that was unnecessary censorship, because his personal life doesn't affect his scholarship, which has its own independent merit.

I would guess it's largely because he writes books about spirituality that his personal life comes into question. Can he be seen as truly wise? I'm not saying he can't, but I think many would sincerely ask themselves that and answer in a negative way.

And maybe they're right to question it.

But between the two extremes of the physicist author and the spirituality author, things get tougher. What about a highly regarded fiction writer with abusive behavior in his past, like the late David Foster Wallace? Love Wallace's fiction or hate it, he made undeniably singular contributions to literature and even ways of thinking about modern society, much of it (we can see more clearly today) by mining very negative aspects of his personality and behavior.

Some people call for writers like Wallace to be, if not censored, then minimized because of abuse in their pasts.

I'm not so sure the tendency to advocate for such things is wise.