The PRH-S&S Debacle and Much More
You are thinking of Houghton Mifflin which. Is now subsumed at HarperCollins. I don't think the name is still used. It was one of the greats.
Where does the old Holt & Mifflin fit into all this?
Maybe. And maybe not.
One could just as easily reach an opposite conclusion: that no mention of Gina’s “retirement” was made in the media because, far from evidence of books and the book industry being of enduring interest or merit, it is a craft so lacking in status or glamour as to have fallen into the La Brea tar pits of our culture and is regarded as of no widespread interest except to a vanishing species of specialists.