Missing older posts

I remember some very nice articles, but they are now unavailable. Error or intention?
e.g. flat x theread or tag and categories

Those (very old) topics were eliminated during the usual forum cleanings.

These topics were very old and out of date, what did you find useful about them? Or did you hit old links in a google search?

Thanks for your question. I created bookmark myself, because the article contained a nice comparison of both principals - flat and thread forum, and above all explained how Discourse solves this dilemma. Do you know about something like that?