IMDB needs to update itself - Tennant was the main villain in the Marvel Jessica Jones series just recently.
Casting an American is not going to happen. More chance of a woman, frankly. As for the timeslot, Who ran in the later part of the year for series 9 and got hammered in the ratings partly because it kept getting shifted to later in the evening because of Strictly Come Dancing. There will be no such conflict earlier in the year.