::It wouldn't make your watchlist long - you wouldn't see anything unless it was created, and once it is you can unwatch once you've voted if you want to.  I don't think a messaging system is worth it just for people that don't want to check their watchlist.  How many such people are there?  I can't see how you can realisticly do much on wikipedia (beyond simply article edits that don't require discussion) without using your watchlist.