Robert, The issue is that no one from Extreme posts the product announcement. I am signed up for the alerts you are talking about and I get notifications when things are posted, but if no one posts it, nothing will be received. For example, where is the announcement for 10.9.1?
I set up an RSS feed from this source and let it tell me there are updates. But to @aeccles point, if no one posts or updates the link, I don't get notified either.