@AllisonMichels as I mentioned in my earlier comment, the specific post that I encountered that was missing was called Use Yammer to make newsletters interesting again! As @NicolasKheirallah mentioned in his post, the original link is here, but it's broken: it just gives an "Access Denied" error.
This is just the post that I happened to encounter that is missing, and it is not yet restored: it's not at the original link, but I also searched for it in case the link had changed, but nothing. I'm sure there are other useful ones that are missing, so it's good to know that you're restoring them.
In the future, I'd suggest that your group not summarily wipe out the entire collection of useful posts and then slowly add content back: instead leave them in place and either modify (if they are still useful with updates/new truth) or delete (totally obsolete) posts as needed over time. That would keep the original information and functionality in place as you make the necessary changes. 
That's weird, It works for me but logged but also in incognito:
Do you want me to save the article and send it to you ?
Thanks for the offer, @NicolasKheirallah, but I got it from the Google Cache. Plus I can confirm what you said: in Incognito/InPrivate mode, it does now show up, so I'm guessing that they put it back online today sometime and my browser is just caching the recent Access Denied page.
I'm glad to see that they're putting the former content back, where it makes sense.
