It's clearly stated in the Upgrade documents that extensions should be disabled before upgrading.
Nothing is mentioned about extensions in the update documents.
My advice to disable extensions when updating is (inherently) not incorrect, but is perhaps absolutely unnecessary.
My stance however remains to limit as much as possible the factors which may influence a process as delicate as an update/upgrade.
RMcGirr83 stated that disabling extensions is NOT necessary for an update.
As long as the extension system is not touched by the update, I see no immediate reason to disagree with this but what if there is a change (no matter if it's only a slight change)? Does this still apply or does this change that "update" into an upgrade?
Is there an official statement somewhere about extensions and updating?
A bug is a feature that hasn't made it to the manual (yet)