I wasn't aware of the Subscribe to Forum feature before, that definitely helps out. But it's still not the most practical solution as most people already get tons of mail, and having to sift through another email every day for a new tournament doesn't seem like an ideal solution.
Now that I've given the issue some more thought, I can't see why we're not already doing it honestly. It seems rather incomplete that we just announce completed tournaments on the site page. Maybe it's just me but I'm not really interested in the results of a tournament I never even knew was going on in the first place lol. The recognition tournament winners are looking for would be a lot more rewarding I'm sure if more people at Smogon knew about the tournaments in the first place.
As I don't visit the tournament page much, I'll admit I don't know how many tournaments are going on usually, so maybe what I'm proposing is an unreasonable amount of work for the site staff. Do tournament moderators have permission to post on the main site? That would make things easier as they have to approve tournaments in the first place. If not I don't think it would be too hard for them to pass the message along to the site staff, as they seem very active on Smogon.
As to whether this is newsworthy or not, again all I can say is that if it's newsworthy to annouce the winners of tournaments, the same should hold true for the start of tournaments.