Someone over on Facebook asked me, so I asked the publisher. They told me

Unfortunately, this title has been out of print for quite some time

I followed up by asking "can I assume this means the book is officially out of print and no new copies will be printed?" and their response was

You are correct – we do not plan to print any new copies at this time.

If you are looking for a copy, you are going to have to keep an eye on the used market.