The WT taught that the resurrected ones would not suffer again the Adamic death of original sin passed on from Adams disobedience ",the wages of sin is death" Rom.6:23 and once you have died you are free from the sin of Adam
So if one is resurrected he/she would never die again because of Adams sin since he/she has been freed from it.
Humans mistakenly believe that this makes them immortal ,that they can never die again and nothing is further from the truth.
{ Although it does make for good horror movies ]
Resurrected humans may very well be free of the inherited death through sin caused by Adam which all of his offspring were subjected to ,however resurrected ones were now living by the grace of God and he holds the right to whether such ones live or die.
just as he does with Angels ,Angels are not immortal ,and are certainly not under the Adamic death sentence.
They live by the grace of God and if and when he chooses their life can be snuffed out.
Their are a few accounts where faithful servants were resurrected and therefore were freed from Adams sin , yet they later died ! why ?
Not because of the sin of Adam , but because it was not in Gods plan before all things came to pass in scripture.
In other words not in his due time .Their is nothing to say he cant resurrect them again if he so chooses.
After all he is the Almighty God isnt he ? nothing is impossible.
If you believe the Jehovahs Witnesses and the Bible.