At Photokina 2020 you will see Panasonic but not Leica!
Leica has surprisingly canceled their 2020 Photokina participation. A German manufacturer not displaying at a German fair is quite unusual. Also Nikon and Olympus will not b e present at the show.
Panasonic has confirmed they will have a booth at the Photokina show that will take place in May 2020.