When auto-updating a plugin the user must rely largely on the browser UI to determine when the page is done loading and the plugin has completed an upgrade.
In particular, if a plugin was activated when it was auto-updated, the second to last step reads "Plugin updated successfully." I have, when distracted, read this many times and clicked off the page, hijacking the final reactivation step. I even did this once on a live site and didn't notice, exposing a bunch of shortcodes that relied on the updated-but-now-deactivated plugin.
At first, the plugin update UI shows a little icon that clearly means loading, but that's only associated with the download. I think the UI needs to
1) use some visual element to indicate progress, and
2) Revisit the names of the steps or add additional text to indicate that users should continue to wait until the plugin has finished updating.
(Also, I just tried to use a ul and ol in the final paragraph, but I think there's an errant CSS style or two for list-items with a lot of padding and bottom-border that shouldn't be applied to the body of Ideas posts.)