The recent rumor of a 5.2mm RF mount wide angle lens coming out sounded too odd to be true. Some hopefuls thought this corroborated rumors of an APS-C sensor camera being released. As expected, the real application for the lens is a niche product. Our money was on it being a security camera lens that Canon, as this is one of many standard focal lengths in that product category, but Canon Rumors today noted that the even-stranger patent story from some months ago regarding a stereoscopic lens for RF mount employes a brace of these 5.2mm lenses.
The idea behind this lens is that two image circles would be projected onto the sensor, and software would then be able to process that to create a stereoscopic image.
Interestingly, such an arrangement could also provide an autofocus system on steroids, providing an enormous degree of parallax relative to a duel-pixel system. This is less likely to be the driver of the design, as existing phase detect mechanisms leave little improvement to be gained.