It's my experience that any comment that goes "you do realize" and ends with "right?" is being condescending in a really churlish way, and I used to do it constantly all the time myself and I try really hard not to do it anymore ever since someone pointed it out to me.

Generally the answer is that no, the person did NOT know that or else they wouldn't have asked the question, and you're just making yourself seem smarter or more elitist by phrasing it as if it should be super simple common knowledge that everyone knows.

Even when its a deep lore cut like that hidden away in a sub note somewhere than a casual player has no reason to actually know.

"Fun fact, every single sentient you fight pre Erra that isn't on the plains literally is hunhow. They're all a part of him." gets the same message across without being rude about it.