CanonWatch indicates it received a tip that canon is working on a 60mm f/1.0. The older EF mount system had a 50mm f/0.95, known equally for its high price and impressive aberrations.
Moving to the 60mm focal length may make sense so as to reduce the sense of overlap with the impressie RF 50mm f/1.2.
A 60mm f/0.95 would likely be catnip for very high-end wedding photographers, allowing them to get a relatively unique look and work in their low-light venues with less reliance on intrusive flash.
Laowa, the Chinese lens designer and manufacturer that has been releasing high quality lenses at a pace faster than almost all camera manufacturers, just came out with its 33mm f/0.95 Argus lens for crop cameras, months after reliable rumors surfaced. This translates to roughly a 50mm equivalent for full frame sensors.