In a sense, that is true, but the sense is a misleading one. They establish that through most of its history, Catholic moral theologians condemned abortion on grounds Catholics no longer find convincing.
Abortion defeats that purpose.
The point is not what happens to the fetus, but what happens to the souls of the consenting partners. This made Augustine condemn sex during sterile periods, after menopause, by anyone who is impotent, or with any form of contraceptive. If sex is allowable for any other reasons but conception, then Augustine's argument against abortion falls. Well, in that case, one must ask the question that Augustine said was unanswerable. Here St. Thomas gave a firm answer.