Nitty Gritty , so the argument appears to be that because the Tetragrammaton is not found in even the earliest of known manuscripts it actually must have been in there originally . That is supposition not fact .
A more plausible argument is that in quotes from the OT the Divine name should be included . However this has been discussed at length and reasons given for the writers to not include it when quoting .
One article which discusses this issue can be found at
I will quote a small part to give a taste ,
" The New Testament frequently quotes the Old Testament . The New Testament quotation sometimes includes a verse that uses the Hebrew name of God . Matthew 3;3 is an example . It says " The voice of one crying in the wilderness , make ready the way of the Lord , make his paths straight " Matthew quoted Isaiah 40:3 and applied it to John the Baptist who made the way ready for Jesus . Isaiah 40:3 used the Hebrew name of God . However , when Matthew quoted the verse he applied it to Jesus by using the Greek word for Lord .However the NWT says " Someone is crying out in the wilderness , " Prepare the way of Jehovah , you people ! Make his roads straight " Again the Greek text from which the NWT was translated uses the Greek word for Lord and not the Hebrew of God .
I have just had visitors arrive and will continue later .Apologies .