According to recently rumors on CR, Canon currently is working on a RF 300mm f/2.8L IS USM lens for Canon full frame mirrorless cameras. This lens should coming along with RF 500mm f/4L IS USM lens sometime in 2020.
Canon is going to announce three new RF lenses in early 2020, expected ahead of CP+ 2020. These three lenses are RF 24mm f/1.4L USM Lens, RF 135mm f/1.8L USM Lens, and a new “first of its kind macro lens”.
According to Nokishita Camera, Samyang will soon announce two new RF mount lenses for Canon full frame mirrorless cameras. These two lenses are Samyang MF 14mm f/2.8 RF lens and Samyang MF 85mm f/1.4 RF lens.