Exactly, the idea that there would be queues of women choosing to go through a full pregnancy to then abort, is ludicrous and frankly insulting to women.
Allowing abortion to full time rather than to what are currently arbitruary cutoff points, given the success of preterm care, would allow a tiny number of women with strong reasons to believe their fetus would be better of not coming in to existence the chance to act on it even in the absence of a confirmed diagnosis.
Examples I can think of is Women pregnant when they get a significant diagnosis in an older child that has a degree of heritability associated with it but that can neither be confirmed or rule out in utero, or a women who has found out she was pregnant late and due to not knowing she was pregnant has exposed her child to significant alcohol (or other recreational or prescribed drugs) in utero, and does not wish to bring a fetus with Fetal alcohol syndrome to term.
These cases will be extremely rare, but the option should be there and the decision should lie solely with the mother.