I have a hard time understanding the "migration", even after reading all the related issues. Homebrew still writes into /usr/local/bin and /usr/local/Cellar, nothing different from the past. What exactly changes?
Writing to /usr/local/bin is not the same as writing to /usr/local. We don't drop a README.md in /usr/local anymore, for instance, and you can change the ownership of /usr/local back to root:wheel after the migration.
Awesome, thanks for that. Would be good for it to be listed on the article. It only tells you that it no longer requires ownership after you have been asked to give it for the migration.