Usually around the time of a DSLR announcement, there's talk about Canon using a third party sensor in the camera. We have always dismissed those rumors and sure enough, the announced camera comes with a Canon sensor.
We're being told that Canon is actively testing a third party full frame sensor in a DSLR. Along with the third party sensor, they're testing the same camera with Canon made sensor.
After Canon's recent development announcement of a 250mp sensor, it's obvious Canon is not getting out of the sensor business altogether, but I suppose it's possible that some non flagship products could see a third party sensor. We don't know the business advantages of using a third party sensor, but we'd imagine it would lower the cost of development.