It's a comment on what some are doing and not doing, they're not applying compression to the pack the same way it's applied in the car, they just use the threads with no compression across the face of the top/bottom modules. I did read one comment saying the Leaf modules have internal compression and are charged and discharged at a fraction of the rate they would be in an EV so don't require as much compression. I'm inclined to err on the side of caution but YMMV hence the question.
I have a 14s2p pack built, 7 modules in series, compressed and BMS connected. About to build the "big" pack with parallel stacks in series.