Because let's not forget, GX isn't gonna be the only realm with any such new feature. And I would really suspect most would rather not have to constantly scroll through what is essentially a pinned equivalent of the never updated and rarely useful ruler bulletin.
It would be the equivalent of one message, not really an amazing amount to scroll through even in a quiet realm. (I regularly have to go down the equivalent of several pages to get past all the turn stuff) So I am not quite sure where in the world you could possibly be coming from. Furthermore, you keep saying it would be another Ruler Bulletin, but I doubt that greatly. Ruler Bulletin is usually for stuff that you don't expect to have to change any time during your reign. This would be more for stuff that is relevant for a week or two, but you expect to change semi-regularly.
For example, you wouldn't put the unit settings for the army in the General's Bulletin would you? So then why would the Ruler put a tournament announcement or other such stuff in the Ruler Bulletin?
