Or fetch the title, pre-populate the submission form with it, and then upon submit, require a confirmation along the lines of "You've changed the title of this

Or fetch the title, pre-populate the submission form with it, and then upon submit, require a confirmation along the lines of "You've changed the title of this submission. Please note that in general, we want submissions to use the original article's title except in cases where it is necessary to edit, for e.g. reasons of clarification or space. We do not allow editorializing in titles, so if this title edit isn't good, your change will be reverted by a moderator and it will not reflect well on your karma score. Are you sure you want to submit with the edited title?"