Thanks, that's fairly clear and concise, at least for the locations you noted.
It does appear to be that in New York it might be required though[1], so it's possibly still a problem depending on area. I'm not going to act like I'm an expert on reading building codes or that one in general though, so I could be misinterpreting it. SF had what clearly seemed like a mechanical ventilation exception in it when I just looked, but SF and Manhattan are the only things I looked up to compare to see if I could find whether it seemed fairly universally allowed or not.
My friend owns a condo in Vancouver. No windows open.
Also Seattle: https://www.reddit.com/r/Seattle/comments/s2s7bx/cant_open_a...
Also https://www.reddit.com/r/askTO/comments/omdxmp/downtown_unit...