bug#38457: 27.0.50; dabbrev-expand regression due to message change

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: Eli Zaretskii <eliz@gnu.org>,  monnier@iro.umontreal.ca,
>   38457@debbugs.gnu.org
> Date: Fri, 13 Dec 2019 00:58:15 +0200
> 
> Really important messages should be displayed permanently in a pop-up window
> like display-delayed-warnings and display-warning.

If you have such plans, I suggest to discuss them on emacs-devel
first.  The really hard nut, IMO, is to decide how we distinguish
really important messages from the rest, and how we communicate this
to 'message'.  In any case, I hope you agree this is not for Emacs 28.

Thanks.