And there's a corresponding article in the NY Times:
The practice of spacing an author’s books at least one year apart is gradually being discarded as publishers appeal to the same “must-know-now” impulse that drives binge viewing of shows like “House of Cards” and “Breaking Bad.”
“Consumers want to be able to binge-read or binge-watch,” Christine Ball, the associate publisher of Dutton, said in an interview. “We wanted to give the consumers what they wanted in this case.”
. . . “I think the bottom line is that people are impatient,” said Susan Wasson, a longtime bookseller at an independent shop, Bookworks, in Albuquerque. “With the speed that life is going these days, people don’t want to wait longer for a sequel. I know I feel that way. When I like a book, I don’t want to wait a year for the sequel.”
The way they put this on Marketplace:
Goldfish have longer attention spans than Americans, and the publishing industry knows it
I don't like to think I have less attention capability than a fish, but I recently read The Baskerville Trilogy by Emma Jane Holloway and I did appreciate that all 3 books were released within months of each other. They're long books with complicated plots and reading them almost one after the other meant I didn't forget things, but unless the author is a speed writer she must have had to hold back the first book for years while she was writing the other two.