As far as I can tell from the videos, the mechanism behind it works by pulling it open, then removing the piece. This is why I'm worried about the centrifugal force...
It is spring loaded, which keeps the sliding collar in place and the two halves locked together. From my little tinkering, there is no way centrifugal force alone could move the collar piece. It is a lot like a compressed air hose fitting, if you are at all familiar with that.
Edit: I see you asked about it as a grip joint. If you are gripping it on the sliding collar only, then there is a chance the weight of the saber could make it slip. In most cases, I would think the other side of the staff would balance out those forces though.