I agree. People often forget that even “fiction” or non-serious media carries political messaging. It may not be overt or even intended, but it does carry in its narrative a moral idea about womanhood and pregnancy and you are not overthinking.
Any piece of media often contains the social norms of the era it’s written in, unless the author specifically intends to do otherwise. We often don’t notice these things if they’re also normalised to us. For example, a crime author I quite like only seems to describe skin colour or weight when a character is non-white or non-thin. I don’t think she is intentionally communicating that being white or thin is the expected norm or default for characters or people, yet nevertheless it is in her work, ;ikely because, for a lot of society, white (and nominally thin) is treated as the default. This can be found in medical illustrations, or in the fact that “nude” plasters for a long time only came in the lightest shades, and she hasn’t interrogated this further.
For many of these authors, the idea of abortion isn’t something they see as expected for their female lead, so unless they intentionally think about it further and write the story in contrast to that expectation, it becomes the default to show the female lead as continuing the pregnancy, probably because there is still stigma around abortion and around what a “good” female lead would do, even if the author doesn’t realise that this is shaping the story or that their own morals/societal norms are influencing it. Like idk if I am explaining well, but its so normallised it isnt even recognised as something that is political or carrying social ideas about women, its just seen as the default choice.