I mostly agree. But really RSS and email have basically the same functionality. The have date, time, content. The main difference is that RSS has better markup for URL "attachments" as well as an alternate URL. The "what if the email server is overloaded" can be equivalently replaces with "What if the RSS feed is down". Spam is an issue with email, the nice thing about RSS is that you know you want the feed, so spam…
I'm willing to bet good money Then if it breaks, you'll neen to find another expensive techie ASAP to fix it, as it's an emergency service. If someone is relying on the alerts through RSS, there's potential for catastrophe in an emergency situation if it fails.
So I'd rather the money go towards tech that gets a message out to as many people as possible, be it through facebook or other proprietary service. Human lives are potentially on the line, so whatever system is used needs to be stream lined the same way existing emergency systems are.