I have no real direct answer to share from the WTS regarding that question. The WTS would not put that in print. I was told by several GB members, that the only official stance of the WTS is found in the printed official publications; not even what is said from the platform is necessarily from the WTS.
Note the change over time: First, in 1973 and 1970
25. Do those congregation members who now abandon harmful addiction need to be rebaptized?
25 Would there be need for rebaptism on the part of those abandoning their addiction to tobacco or other harmful product? No, this does not seem necessary. Knowledge brings responsibility and educates the conscience. (1 Tim. 1:13) The congregation gave them to understand that their practice did not ‘prevent them,’ and they were baptized in accord with that understanding. (Acts 8:36) Of course, if an individual feels that he presented himself for baptism with a ‘bad conscience’ due to such practice, he may decide to be rebaptized.
Some may have been immersed in association with the theocratic Christian congregation but without having studied the book “Your Word Is a Lamp to My Foot” and without an understanding and appreciation of dedication. Such persons may have wondered if they should now be baptized or perhaps be baptized again. Yes, they should, if they had not truly made a dedication before they were baptized but now are disciples, having come to a knowledge of the truth of God’s Word and having made a dedication to do Jehovah’s will.
Under what circumstances might rebaptism be considered?
What about an individual who was not practicing sin at the time of his baptism but whose subsequent wrongdoing required the formation of a judicial committee? Suppose he then claimed that he did not fully understand what he was doing at the time of his baptism and said that his baptism was not truly a valid one. When meeting with a wrongdoer, the elders should not raise questions about his baptism and ask whether he feels that his dedication and baptism were valid. After all, he heard a Scriptural discourse about the significance of baptism. He answered affirmatively questions regarding dedication and baptism. Then he changed his clothing and was physically immersed in water. It is, therefore, reasonable to believe that he fully understood the seriousness of what he was doing. The elders would thus treat him as a baptized person.
If the individual raises the issue of the validity of his baptism, the elders may direct his attention to The Watchtower of March 1, 1960, pages 159 and 160, and February 15, 1964, pages 123 to 126, where the matter of rebaptism is discussed in detail. Eventual rebaptism under certain circumstances (such as a lack of sufficient Bible understanding when one was baptized) is a personal matter.
Cases of rebaptism in the Bible:
In the course of events, while A·polʹlos+ was in Corinth, Paul went through the inland regions and came down to Ephʹe·sus.+ There he found some disciples 2 and said to them: “Did you receive holy spirit when you became believers?”+ They replied to him: “Why, we have never heard that there is a holy spirit.” 3 So he said: “In what, then, were you baptized?” They said: “In John’s baptism.”+ 4 Paul said: “John baptized with the baptism in symbol of repentance,+ telling the people to believe in the one coming after him,+ that is, in Jesus.” 5 On hearing this, they got baptized in the name of the Lord Jesus. 6 And when Paul laid his hands on them, the holy spirit came upon them,+ and they began speaking in foreign languages and prophesying.+ 7 There were about 12 men in all.