Not at all. Never know when someone reading a press release may pass it on or get involved personally, even if the event/project is not directly related to their mission. I'd include fraternal orgs, also.
Have you ever talked to Keene or others about pooling resources to build such a comprehensive listing? You would also have to have dedicated people to continuely update and purge. There are whats called LISTSERV companies on line that you pay to create, manage, and broadcast your email lists, but they mostly deal in commercial applications.
L-Soft Catalog of LISTSERV lists
If you have a committee or volunteers in place who are already doing this, I'll be happy to assist where I can. But it's more than one person can do from my experience.