Any approach to broadcasting a message to the entire community which actually selects recipients based on their knowledge of an arcane technique (whether that's checking google's cache, the wayback machine's cache, or your own local cache) is not a good solution, in my opinion.
On one hand, we can try to educate our members now, while things are tip-top; they can bookmark those other channels for later reference. But what we really want is an effective way to react when the site goes down and users want to know where to turn for answers. Putting the info on the hag-seed hence page clearly makes a lot of sense. Aside from that, what else might a befuddled user do to get answers? Maybe perlmonks down. In that case, maybe we should make an authoritative page which will pop to the top of the results for such a query.
But we've talked about this before. See Re: Site back up again for one starting point.
(I have a feeling it was also discussed around the time of What happened? and Status of Recent User Information Leak.)
I reckon we are the only monastery ever to have a dungeon stuffed with 16,000 zombies.