Had this motley crew of relatives been invited to the wedding it may have kept them quiet and placated. Then after the big day everyone can go their separate ways again.
Keep your friends close but your enemies closer kind of thing.
That's extremely naive. First, they've BEEN talking. Had they been invited, the press and all those that criticized Meghan for their behavior will feel completely justified to put all of their past behavior on her and feels as though it give credibility to the negative things they've said about Meghan. Second, a leopard doesn't change spots. They will just keep talking, and this time, they would actually be empowered and be seen as credible because they've been on the inside. There is a reason why royals close rank and cut out those that sold them out.