This is one of the reasons that the "people with breasts" wording doesn't work.
Someone who's squeamish/worried about removing a woman's upper clothing to do CPR in case they see/touch her breasts isn't worrying about her cup size.
Many men have more breast tissue than many women, mostly due to weight but also hormonal issues such as prostate cancer etc. I doubt anyone's thinking about those men's breasts before they whip the tshirt off, whereas a woman with small or no breasts may still run the risk of suboptimal care.
Edit: xposted with everyone. That's good they've made an update. PWB is still superfluous given the message they're delivering, but they'd get it in the neck either way so good on them for taking feedback.