Often there are contrib or user errors that break Drupal administration functionality. Once the underlying error is fixed, a cache flush is needed to clear these errors.
One example of this is:
It use to be possible to use update.php to flush the cache, but due to UI enhancements, this is no longer possible. I have personally used this maybe 100 times in D6 to flush the caches.
This leaves no options other than creating a custom update script or to manually flush the caches via sql. Not something that most users would be able to do.
So maybe there needs to be an option to continue even when there are no updates pending or an alternative mechanism for doing this.
Marking as a bug as it is a regression from D6 (sorry this is brief, typing one handed with a broken humerus)
PASSED: [[SimpleTest]]: [MySQL] 36,983 pass(es).
PASSED: [[SimpleTest]]: [MySQL] 33,804 pass(es).
FAILED: [[SimpleTest]]: [MySQL] 33,804 pass(es), 2 fail(s), and 0 exception(es).
FAILED: [[SimpleTest]]: [MySQL] 33,738 pass(es), 24 fail(s), and 46 exception(es).
PASSED: [[SimpleTest]]: [MySQL] 33,803 pass(es).