You know, actually, this does happen At least in Romania (I did not have time to search for the subject if it happened in other countries too). But in Romania, during past years, multiple teams demoted to second league started with a negative number of points. This happened for same reason: during the previous year, the teams did not pay their players.
That happens in other leagues too, but always as a part of punishment and not just because team won the championship (like it would be in this case) as it would be quite unfair.