This is not a hill I'd want to die on, but I do understand thinking this photo is fine. If I hadn't been told it was from Playboy, I wouldn't give it a second thought. It's a conventionally-attractive woman in a hat showing a little shoulder. I wouldn't be upset over Michaelangelo's David either. It is less sexual than like 90% of modern TV or mass-market advertising. I suspect a similar image of "cleaner" provenance would not garner much attention at all, honestly.
But it is weird that an image from such a source was chosen in the first place. It is understandable that it makes people uncomfortable, and it seems like there should be no shortage of suitable imagery that wouldn't, so...easy sell, I'd think.
On a related note, boy oh boy am I tired of every imagegen AI paper and project using the same type of vaguely fetishized portraits as examples.