clarification/removal needed: docs recommend upgrading with authentication disabled
This  is a bit that was initially included in 2013, and has been moved around since then. It states
Important When upgrading, we recommend expressly disabling authentication first, then perform the upgrade. Once the upgrade is complete, re-enable authentication.
I find it weird that we are recommending disabling authentication during an upgrade.
IIRC, I haven't seen anyone explicitly disabling authentication during an upgrade for years, and it would be nice to do one of two things:
1. remove this notice; or,
2. explain in which circumstances this would be advised.
Definitely drop the "recommend" keyword though. I don't think we should be recommending any of that :)