If Italy is pushed out of the Six Nations, they’ll have some say in the matter.
When Italy was added to the competition in 2000, they purchased a stake in ‘rugby’s greatest championship’. Its unclear if that purchase was an equal stake (one-sixth of the operation at the time) or if they purchased only a sliver. CVC’s equity purchase was for one-seventh of the competition. Unions received disproportionate payments as a result of the deal, implying that teams held uneven amounts of the competition.
One way or another, any changes to the Six Nations will require, at least, a vote of the shareholders. That’s a vote that will include Italy.
The Azzurri could have even more power than that. The Times in the UK is reporting that Italy maintains veto power on the move. Its unclear if that veto means that any change must be unanimous or if the power is more limited. If its correct, the only way South Africa could join would be through an expansion.
Finally, there’s the question of Italy’s financial stake. Dropping them from the Six Nations Championship is one thing. Removing them from the Six Nations business could be even harder. Presumably, the shares belong to F.I.R. until they choose to sell. That’s the same issue that made any potential relegation impossible a few years ago: excluding Italy from the competition doesn’t exclude them from the financial benefits. Unless there’s some sort of option language bound to Italy’s stake, they don’t have to leave the business until they decide to leave.
None of this makes a change impossible. It does make it incredibly challenging.