BBC announced a special panel during the virtual Comic-Con@Home that’s going to happen this July, so Radio Times guys recorded this podcast about the subject (the identity of that person).
That virtual Comic-Con@Home will be featuring the current stars Jodie Whittaker and Mandip Gill, the newcomer John Bishop and the showrunner Chris Chibnall also, and it seems likely that the panel will grant fans their first look at series 13 images or footage, and even a trailer.