I second this, in addition, the injection is not only related to EOS/EOL for modems it is also for when you are approaching your data cap. Which is rather annoying because it actually can halt your gaming or netflix experience oddly. I have had both happen, one I was playing PlayerUnknown's Battlegrounds and the game crashed. Since the game itself uses web based tools, for its menu system, upon restarting the client a Comcast injected message popped up warning me I have used 90% of my data cap.
The same thing happened on Netflix ...