I'm starting to think that maybe she really didn't care about the fusion. Think about it. When Ruby and Sapphire escaped, why didn't she send anyone after them if she was so hell-bent on shattering Ruby and getting Sapphire back? I mean, surely she also valued Sapphire and her future vision enough to keep her, since Sapphires are so rare. In hindsight, I'm thinking that she was just lip-servicing the rest of her court, simply saying what they were expecting her to say in order keep up an appearance and to hide the fact that she just didn't care. And in the most recent episode, the same Ruby and Sapphire that committed the "unheard of" act of fusion were right in front of her and she barely did anything more than bat an eyelash. The SU wiki states that she possibly didn't recognize them, but how can she forget the two gems who basically had sex right in front of her and her whole court, and at the same time letting Rose Quartz and Pearl escape? Who can forget that, even after five millennia? I think that if she really wanted it done, it would have been done a long time ago. But from Garnet's point of view, she really did want Ruby killed, so she still holds a grudge.