Hey that's a good tip, I didn't know about fullscreen status being a signal for busy detection. This is a useful tip for me personally that I'll start using, thanks!
That doesn't quite resolve what I'm talking about. Keeping apps full screen isn't realistic for me, since I'm app switching all the time and often need multiple apps side-by-side, especially when coding. And again, my main goal commenting was just to challenge the very idea that chat status should be minute-to-minute accurate. I don't want that idea to spread, I want people to expect to wait for a response, I want chat to be default asynchronous, and for people to just be happy when they occasionally don't have to wait.
By and large this just isn't a big problem for me, it's a totally minor issue, but would be nice if we collectively have the same expectations. At my work, people mostly do use chat asyncronously and don't start chats with just "hi" waiting for a response. I'm personally relatively happy with my work interactions, but I'd prefer if attitudes didn't shift in the direction the article is advocating.