In my experience comparing Slack vs HipChat (limited experience, but still), Slack's notifications were more reliable. As in, Slack was smarter about figuring out when I'd locked my laptop, or the screensaver had activated, and then it would re-route notifications to my phone. It does this pretty flawlessly, compared to HipChat that would mess it up sometimes (and so we were never quite sure whether to trust it).
This is where the article lost me. How are Slack notifications different from those in other services? I'm just not getting it.
To me, this is an example of somebody wanting to love something.