According to CR, Canon currently is accelerating the development of EOS R “Pro” full frame mirrorless camera. The EOS R Pro is known as mirrorless version Canon EOS-1D X Mark II or 1D X Mark III, designed for sports, wildlife photographers.
Source said that this Canon EOS R Pro will coming along with EOS-1D X Mark III in early 2020. Though EOS R Pro could be just a development announcement, Canon may also announce several new RF super telephoto lenses at the same time. Canon currently already have some RF mount super telephoto lenses patents: RF 400mm f/2.8, RF 500mm f/4, RF 600mm f/4 and RF 100-400mm, RF 200-600mm.