I can't imagine sitting down and making myself watch open heart surgery or some other invasive procedure before having it done, so no, watching any kind of video on an invasive procedure wouldn't stop me from having the procedure if I felt it was necessary or preferable to not having the procedure.
If watching the video, or series of videos, was likely to add more tension to a decision I have already chosen, I would find a way to block it out as I am not a masochist who's gonna lie down for a sadist or sanctimonious shit.
I'm pro-choice on much more than whether a woman has the right and responsibility (they are not mutually exclusive) to make a decision that has such an impact on more than her body, for her entire life--and if she keeps the fetus to term, then she has the responsibility that goes with bringing up a baby through adolescence into teens and perhaps beyond if she helps her offspring get an education, or the child has severe physical problems.
If she carries the fetus full-term and has what will then be, outside the womb, an infant, she'll have to live with all that goes with that decision, too.
Pro-choice isn't just about having an abortion; it is about choosing not to, or choosing to go full-term and put the child up for adoption, or make another arrangement such as having--if available--a grandparent do the rearing.
The idea that others feel they have the moral right--and may actually have the legal right in some locales--to force someone to watch more and more emotionally upsetting videos "to make sure the person is fully cognizant" will make sense--though I still will not agree with the so-called reasoning behind it--when it's done across the board for procedures from face lifts to limb amputations and everything in between.