Admittedly, the Missouri ban was wrapped in a package with other measures, so it wasn’t the main focus. But still, this establishes that RCV does not have the momentum its advocates claim it does. They spent over $100 million on these efforts, and only lost.
The electoral reform movement needs to recognize RCV has become a stumbling block. Even if you remain convinced it is better than the status quo (which I would contest), it is sapping resources and attention, and prompting organized efforts to stop any reform whatsoever. It is entirely possible that, because of RCV’s utter failure, no more progress can be made for the next several decades.
In short: Continuing to support RCV will likely only perpetuate the status quo. Drop it like a hot potato. Move on to other efforts, like Approval, or STAR.