Yes. I generally use it to tell whoever is on the other side just how annoying and misleading the chat ping sound was and the blinking of the tab title. Intentionally trying to sound and look like a Facebook, Skype or Gmail notification. Thats definitely not a dark pattern. The sort of company that would use this isn't scammy at all.

The ding for the chat is fake, though. There's nobody on the other end waiting for you to return their engagement.

I had opened it and faked interest, waited for 30 minutes, no reply. There is nothing wrong with providing a chat function but in this case it made a notification sound and displayed a "1", implying a message for me. That is just scummy.