A ton of the courses draw from this fella. You get online access to the book for free once you start but it's a solid reference anyway, especially if you're thinking about going for CISSP as well, which I totally recommend due to the massive overlap.
Are you asking if this book is availed, or something else? If it's this one, it should drop May 25th.
However per the author's own comments there's very little different between the 8th and 9th edition. As I understand it, the OSG (by design) goes into significantly more detail than the CISSP exam itself requires, as the CISSP is more about applying concepts, making architectural decisions, and value judgements than explicit technical details. To this end, I doubt your few aspirants will find value over waiting for the newer, more expensive text to drop.
I don't see it listed on ISC2. Others might be able to help. But I looked at ISC2 website. I didn't need to buy $600 to pass this exam.
ISC2 Study Guide and Resources page - https://www.isc2.org/Training/Self-Study-Resource
(ISC)2 CISSP Certified Information Systems Security Professional Official Study Guide
9th Edition
https://www.amazon.com/Certified-Information-Security-Professional-Official/dp/1119786231
Bundle - Guide and Practice tests ~$85 - https://www.amazon.com/Certified-Information-Security-Professional-Official/dp/1119790026/ref=bmx_s088cp2o_3/141-8537478-8860806?pd_rd_w=hqx44&pf_rd_p=1f75fbb3-7d95-464f-8182-952155c0316b&pf_rd_r=ZSSW7KKNHJGYBWFB6TVZ&pd_rd_r=b92f4ac8-f1ff-4227-8efa-aa8f5df694a9&pd_rd_wg=JBQy5&pd_rd_i=1119790026&psc=1
Now there are kindle versions...
https://www.amazon.com/Certified-Information-Security-Professional-Official/dp/1119786231
Also do remember that it is illegal to use those scanned to pdf versions (if there will be any).