About appt-update-list local hook

[Gabriel <gabriel376@hotmail.com>]

So I have been playing with Calendar, Diary and Appointments
lately. According to the documentation[1]:

"The appointments list is also updated whenever the diary file (or a file
it includes; see Fancy Diary Display) is saved"

But it was not working using Emacs built from master branch. Then I
discovered that commit '587a97bcb23bc6ea429ab790efa03f2260a9bca8'
changed the hook to be local mode. With this change, the diary-file is
tracked for changes only if 'appt-activate' is called inside a
diary-file buffer, but I call 'appt-activate' inside my init file. I
could not find any bug or thread linked to this commit, and the commit
does not contain any descriptive information. The commentary of appt.el
and the docstring of 'appt-update-list' also indicates that the
diary-file is always tracked for changes, regardless of how/where
'appt-activate' is called.

Is correct this local hook ? If so, should we update the docs ?

[1] https://www.gnu.org/software/emacs/manual/html_node/emacs/Appointments.html