I have a writer friend who mentioned last year that after quite a few published novels, she was going to be curious to see how her most recent novel did. She said her editor had more input on this book than any other, basically giving the author the subject matter to write about. The book sold very well, better than any of her other previous books, even making bestseller lists.
I wrote this off as a one-time thing, but then I recently heard from another writer, with whom I share an editor. She said that our editor told her that the imprint would be publishing fewer books and as a result, the editor wanted to make sure she got exactly the books she wanted. The editor told the writer that she wanted a novel on a specific topic. The writer was offered the opportunity to write that specific novel. (Both of these writers are with Big 5 imprints.)
Now, two does not make a trend (not even for the New York Times Style section), but it made me wonder: Is this a thing? Editors asking for specific novels to be written? I understand this in nonfiction, but hadn’t realized this happened in fiction. Are we all destined to all be works for hire?
First, let's get our terminology clarified. Just because an editor asks for a particular kind of book does NOT make it a work for hire. My guess is your writer friends had standard publishing contracts with advances and royalties and (here's the key part) they retain the copyright to their work.
Now, to what you're actually asking about.
This happens ALL the time. I've got a client who has had 10+ books published and his editor suggested an idea, and my client wrote the book. I'm not sure the editor ever mentioned to the sales team that the ideas was his. He certainly didn't push it any harder than he did the other (not-his) books my client wrote.
Editors hear about books the sales team is hungry for; editors then pass that along to agents and writers.
When you see editors tweet about their manuscript wish list (#MSWL) it's exactly this kind of thing. Editors don't dream up projects based solely on their own idea of what would be good to read. They're listening to the sales and marketing team, who are talking to booksellers and librarians, who are talking to library patrons and readers.
It's not efficient communication by a long shot, but then this is publishing. For efficiency, you need to go someplace else.
Don't worry about this. Write the best novel you can.