Regarding the currently proposed user option, does it make sense to you
to have such option that decides whether package-install upgrades
built-ins? Whereas one can always upgrade a built-in package using 'i'
(package-menu-mark-install) in the list-packages menu, no matter the
value of that option. I get the backward-compatibility intent, but user
options should also do something logical from a user's point of view.
All these questions should have been raised and discussed months ago.
Then we could have done the best for the users (what that is, is still
unclear even at this point). Now it's too late, and the main factor
that will decide how Emacs 29.1 will behave in that regard is whether
the changes to implement that are safe enough to go into Emacs 29.1.
To answer your question more specifically: yes, it does make sense to
me. The logic, so it seems, is in the eyes of the beholder, and my
eyes do see a certain logic there.