No, it is not possible to change the Insert Routing via MIDI CC.
One option would be to have duplicate Programs where one has the routing off and the other has the routing in parallel. Then you can just send a PC message to load the different Programs and the spillover should make the change smooth.
What is the device you are using as an insert? Can this be controlled via MIDI? If the device has kill dry or an output level, you could bypass the insert on the device or turn the output level down to 0 and that should resolve the issue.