In my case, it was in 2017, and I remember clearly what happened. Homebrew alerted me about the most recent compatible formula, and what commit it was removed in a week earlier. I was then forced to unshallow the Homebrew repo, revert that commit, and then I could install it. I remember I had a good reason for not updating my OS, and I'm sure it was less than two years old.

It was incredibly frustrating, and took a lot more effort than it was worth. Homebrew already had the ability to find the last good version, it would not have been hard to automate it. There were no taps at the time, I had no choice but to do it manually.