The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
The adventure you have ordered is 10-22, not 15-22. He probably mentions the 7-9 level range because there is some advice to start it around there, if you want it to be super-hard, just like the original. Its bad advice IMO, you are better served with doing something else, if that is what you want.