In fact, learning about that list (an seeing the logs online) made me first think of how nice such an RSS would be. I didn't subscribe to the list because of all the downsides you mention. It just doesn't give me what I want (extras above all), but gives me a lot of unwanted noise. On my tablet, yes. But it doesn't show here in the office or wherever I am without my tablet. Also, while this mechanism actively informs me about updates of software I have installed, it doesn't do so for new packages that become available or updates of software I don't have installed.