To a large extent, it is an illustration of some particular lawful excuses that would apply, but it makes it crystal clear up front that this offence does not intend to bring within its scope the kind of ordinary legitimate repair and modification that could result in one or more VINs on a vehicle being modified or removed entirely.
There are up to 17 VINs on vehicles. They can be on places like the door, so if a door is involved in a collision and is removed, then a VIN will be removed. The intent of this offence is not to capture that kind of activity, and it makes it clear up front so that the people engaged in those industries don't have to worry about going into court and defending themselves on the basis of this being a lawful excuse.