The reason that those changes have been made was to prevent poor quality questions from being dumped on another unsuspecting SE siteprevent poor quality questions from being dumped on another unsuspecting SE site. There's no reason to turn around and make it easier again.
If you come across a closed question that you honestly think is of high enough quality that it should have been migrated to another site, then you can flag it for moderator attention to have it migrated. Moderators can migrate questions even if they have already been closed.
The system already solves this problem. I can't see the need for a new feature.