Canon has released cinema lenses in the RF mount:
CN-R 14mm T3.1 L F
CN-R 20mm T1.5 L F
CN-R 24mm T1.5 L F
CN-R 35mm T1.5 L F
CN-R 50mm T1.3 L F
CN-R 85mm T1.3 L F
CN-R 135mm T2.2 L F
The CN-R 14mm, 20mm, and 24mm primes are $4,220. The 35mm, 50mm, 85mm, and 135mm primes, are $3,950. More lenses are said to be coming in this lineup.
The lenses weigh between 2.86 to 3.3lbs each.
Based on these focal lengths and T stops, it appears that they have taken their existing EF mount cinema lenses (CN-E) and changed the mount and possibly made other tweaks for this set. I will try to verify if this is the case. They claim compatibility with 4K and 8K video capture.