Why did they (The Society) have to add to this scripture, giving a totally different meaning to the original understanding.
Because the Watchtower Society does not teach that dead bodies will be resurrected !
The Watchtower teaching is that the original body will remain forever in the grave rotting. Their concept of resurrection is that Jehovah will find some dirt somewhere else and re-create from scratch the person who died. This new person will look and act just like you, however the original body (and logically person) will remain dead forever.
According to Wt teaching all that person is is really their body (since they don't believe in an immortal soul) and since their body never will be resurrected, logically no witness who died will ever really live again, they will only be replaced by a new person who looks like them.
I recently shared this doctrine with a long-time witness who had always thought that his body would be resurrected. After he saw that this was no so, he was quite shocked. Its quite an experience to realize that your body will remaiin dead forever in the grave.
The watchtower religion is hopeless for those who have died.
The Bible however teaches the resurrection of the original body (in a restored state).
As a side note the NWT also translates Lazareth's grave as being a "memorial tomb" hense a literal grave, contrary to their standard doctrine that "memorial tomb" reallly means a memory center in God's mind and not a real grave.