The log was from the (one and only) new LG drive. It seems that LG have put new innards in the drive (Mediatek MT1959) but not changed the model number (WH14NS40), just stuck an SVC Code NS50 on the outside label as well. So it appears to be a WH14NS40, except it's not!
Like you, I am also confused why a manufacturer would do something so seemingly nonsensical. Thankfully, picking the wrong firmware didn't brick the drive, but if it did, LG would have a lot to answer for.