confusing pull -u behavior

[Felix -]

what I'm wondering is, when do you ever want the existing "pull -u"
behavior (only update if changes got pulled successfully), rather than
the proposed new command (always update if pull succeeds, whether or
not new changes were received)

is there any benefit to keeping the current behavior?

yes, you can do anything with shell scripts or configuration, but it's
important to have a good out-of-box experience.