Right, so why hasn't that been implemented?
Because it is not a priority.
I'd argue that out of all bitcoin development going on, this is probably the most important. Because if you're going to get any other updates/changes through, you need to actually inform people of them in the first place!
No. An alert system should only ever be used to inform users of security problems or forking events. It should never be used to inform users of updates, software improvements, new versions, etc. that are not related to the security of a user's coins. Any sort of intentional fork should never be announced over any alert system.