According to latest rumors on CR, Sigma is rumored to make several RF mount mirrorless lenses for Canon EOS R system. These lenses will exclusively designed for RF mount, I think it will be similar to current Sigma DG DN E-mount and L-mount lenses.
Sigma has already released their E-mount and L-mount mirrorless lenses since mid-2019. According to latest rumors, Sigma will also release there RF -mount mirrorless lenses in early 2020, probably around CP+ 2020. If true, it would be great for the EOS R system.
First 3 Sigma full frame mirrorless lenses now leaked online, will be available for Sony E-mount and Panasonic/Leica L-mount, Sigma may also release RF mount full frame mirrorless lenses later this year to early next year.
The new announced Sigma 70-200mm f/2.8 DG OS HSM Sports Lens (B&H Photo Video)for Canon EF mount will be available for pre-order on November 16th, 2018. The Japanese price for this lens will be JPY 164,600, US price will be around $1,699. The release date for this lens is on December 14th, 2018.
Sigma will soon announce five new lenses for the upcoming Photokina 2018. They are Sigma 28mm f/1.4 DG HSM | Art Lens, Sigma 40mm f/1.4 DG HSM | Art Lens, Sigma 70-200 mm f/2.8 DG OS HSM | Sports Lens, Sigma 60-600mm f/4.5-6.3 DG OS HSM | Sports Lens, Sigma 56mm f/1.4 DC DN | Contemporary Lens (Sony E-mount or MFT mount). Below are first images of these lenses:
For this upcoming Photokina 2018 in September, Sigma will announce a new 70-200mm f/2.8 DG HSM Sports lens. Available for Canon EF mount, Nikon F-mount, and Sony E-mount. Sigma is also rumored to announce a 70-200mm f/4 DG HSM Contemporary lens.