Wouldn't that be better to be done in the forum ?
I mean, leave the announcements as they are (after all it's part of md itself the way its announcement was made) and maybe open a topic where there will be reference to each announcement (having categories like "rules", "scene changes", "creature changes" etc , those are a quick example) and make sure that this topic stays updated so anyone will be able to look for announcements and cross reference each one with the ones its related
The massive number of announcements currently existing would be an issue (time consuming and integrity ) but it's not something that can't be done (i think )