That's interesting. I felt like Nocturne was trying to jog memories and was sad to see they didn't emerge. I think it was the braiding hair line. I also felt like the noblestalk conversation was an analogue for nocturne coming out as trans. Funny how different people read different things into the same conversation, isn't it?
Nocturne called it "small things you would've forgotten anyway even without the memory loss". I think she wouldn't have worded it that way if it was something more serious, but I can understand if you assume Nocturne simply didn't want to stir shit because Nocturne knew Shadowheart was in a new relationship with the person right next to her. This situation is actually somewhat up to interpretation, indeed.