Good observation, and well written article. On this, though: "new DNS records are actually available instantly" Depends on who is serving your DNS records and

Good observation, and well written article. On this, though: "new DNS records are actually available instantly" Depends on who is serving your DNS records and what sort of interface they give you to make updates. There are many where your update makes an update in a separate database and the actual zone file updates are batched every X minutes. And on this: In the 90s, maybe DNS records really did take multiple hours to get “propagated” and pushed out, and so it was more accurate to use the term “propagation” to describe why you needed to wait? Things aren't technically substantially different than they used to be. People probably used longer TTL values, but that would be by choice.