Could be a good idea, but it would be limited to events which received official backing from bitcoin.org so there would not be many of them. Alternatively, bitcoin.org may consider charging a fee to people who would want to announce something on that page. The fee would cover the time necessary to check the event's value.
Thanks for your ideas. I'm willing to give it a try without asking for fees. I doubt that there will be enough events to cause problems. Organizing a conference or anything serious involves costs and a lot of job. And as long as the events are focused on Bitcoin and have a clear website, promoting them doesn't require much verifications and it is just good for everyone. I am thankful that there is people in that community working to create such events.
That said, that makes me think that it might be good to mention on that page that those events are held by different organizers.