Chats are ambiguous because it functions both as sync and async. I treat my whatsapp messages as async, but time and again I get heat from people because I take too long to reply, something I'll never feel the urge to apologize for.
I see this in the opposite direction at work. I'll send someone a chat message after their working hours and they'll actually reply apologizing that can't look now and will reply tomorrow. Or that they're just waking up and they'll look later today. Yeah, that's what I expect, I'm not your boss asking you to come in on a Saturday. Why on earth are you looking at your work chat outside of your work hours anyway??
I see this in the opposite direction at work. I'll send someone a chat message after their working hours and they'll actually reply apologizing that can't look now and will reply tomorrow. Or that they're just waking up and they'll look later today. Yeah, that's what I expect, I'm not your boss asking you to come in on a Saturday. Why on earth are you looking at your work chat outside of your work hours anyway??