Rumor has it that an RF 14-21mm f/1.4L lens for the Canon EOS R system is currently in advanced development stage and will likely be one of a couple of world’s first lenses coming for the RF mount in 2020.
There is an US patent application (2018-0314060) which supports the rumor.
We are usually cautious with rumors about gear which is said to be announced much later, as it is in this case. On the other hand, Canon stated more than one time that the RF mount will allow them to build “world’s first” lenses, hence a RF 14-21mm f/1.4L lens is in the realm of possibilities.
For a list of existing lenses for the Canon EOS R system have a look on what is on display at CP+ 2019.
Source: Canon Rumors