On paper, this merger is deplorable and should be blocked. As book publishing consolidates, the author tends to lose — and, therefore, so does the life of the mind. With diminished competition to sign writers, the size of advances is likely to shrink, making it harder for authors to justify the time required to produce a lengthy work. In becoming a leviathan, the business becomes ever more corporate. Publishing may lose its sense of higher purpose. The bean counters who rule over sprawling businesses will tend to treat books as just another commodity. Publishers will grow hesitant to take risks on new authors and new ideas. Like the movie industry, they will prefer sequels and established stars. What’s worse, a giant corporation starts to worry about the prospect of regulators messing with its well-being, a condition that tends to induce political caution in deciding which writers to publish.
All these things have happened already.
But you are right, they will only get worse.
I was an editor in the industry until I got out in 2013. Going back to my entry-level job in 1996, it got harder and harder each year to “protect” our authors from the creeping consolidation zombies. Middle management was incentivized to clear a path for corporatization — and they did an admirable job selling us all out: Authors, editors, staff, and vendors. The fish rots from the head, as the expression goes. The rot permeated the whole ecosystem, now the smell of mildew has all but overpowered that clean creativity scent.