Oddly enough, I can confirm having heard something along the very same lines you mentioned, in that commrnts were made by a visiting speaker to our cong back in the mid 70s. As far as I can recall, he did say that fetuses had to be "living" souls to qualify for a resurrection, and simply being "alive'' was not enough. I remember his somewhat sepentine logic, as he argued the hair-splitting meaning of "living" and how that something that was "alive" was not necessarily "living"
Whether the WTS still maintains this position I do not know, since their publications make no mention of this. Of all the ethical decisions individuals have to confront in a culture that is growing more and more secular, few are as complex in the application of basic principles than the matter of abortion. Unfortunately, the Bible does not confront this issue per se, except insofar as to condemn murder, which according to various debating principles may or may not apply to fetuses in a womb.
There is one possible mention of an abortion, at Ex 21:22,23, which tells of the consequences of two men fighting near a pregnant woman. The scriptures say that should a fatality occur, the guilty party would need to die. However, the "fatality" mentioned may not be a miscarriage, [hence by implication an abortion] but the death of the woman. Most commentators feel that that seems to be the intent of the biblcal passage. The WTS refuses to recognize the inherent ambiguity of the text and implies that it categorically refers to an abortion. Reasoning pg 25
The WTS takes advantage of the fact that the Heb "Nephesh" has a complex series of meanings and an equally complex series of applications. Indeed, it does appear in some passages to confirm the WTS idea that the "soul" IS the person, but they also either deny, or redifine, those portions of Scripture that clearly show that the "soul" is something cognitive IN a person, which leaves the body at death, [Gen 35:18] and enters on life [1Kin 17:22]
I feel that as men, we have no right to impose our moral judgements on women who have to bear the burden of making decisions that concern the operations within their own bodies. As a commited Christian, a conviction to which I was led after realising the foolhardy theology of the WTS, I am personally against the idea, but I hope that I am mature enough to accept the opinion of women who differ.