If what you claim about publishers want to sell is true, Its profiteering. It's not like they are sitting on the huge inventory that they can't do away with and it's costing them to hold on to that inventory (even if they did, old inventory without changes means nothing to them).

They have rights, they could always print and sell with a positive preface saying, look which ideas were normal when the book was first published in the year xyz and see how far we have come etc. With the controversial content, arguably, the books would sell more.

If anyone changes a book content without the explicit permission of author (if he or she is dead, then no permission by default) then they should not sell that stuff in author's name. It should be that simple. They can repackge it and call it a sanitized version of xyz by abc and then see how many people want to read that. (There could still be a pull for this, I am thinking Stephen Fry telling us about Mythos, that's essentially retelling, publishers need to have guts to do that rather than tampering already existing works of other authors)

To nullify the classist effects you would have to let people speak the way they want to and then we are back to square one.