I am afraid it is so. I was at the Bookpool warehouse a week or two ago and they were in the process of closing down. They were selling their [empty] metal shelves even as I was shopping. I was able to talk to the owner and it is unclear whether the closure is permanent or temporary. The owner did not know whether Bookpool.com would stays closed, reopens or opens in a new form and how long it would take to make that decision.
The number of shelves still containing books was about half of what they were a year ago. I am surprised that they had to shut their "doors" so soon. I am assuming that they are closed based on the website, www.bookpool.com, current state. The webpage that is currently showing up at www.bookpool.com does state "coming soon" so hopefully, the closure is temporary.