I would have announced a doctory male actor and a female actor so that everyone would assume she was the companion when the location photos started to leak and then do the switcheroo at Christmas and surprise everyone.
They’re running a business, right? I’m assuming the way they did will drive bigger ratings.
They are running a public service broadcaster by royal warrant, technically they aren’t supposed to think about running a profit but they do.
I think these leaks are more to try and turn the inevitable leaks by the tabloids into something positive but the power of surprise is tangible and if everyone found out on Christmas day the new Doctor was a woman you can bet your bottom dollar even people with very little interest in the show would tune in to watch the first episode just see what the fuss was all about.
Giving it a half a year to stew as they have some of that expectation would have worn off by the time the first episodes with the 13th Doctor start showing. BTW they should have done this when Tom Baker left as they had done the Doctor getting younger thing to the point of breaking. Maybe the Doctor should be female for the next 13 incarnations. Plenty of great actresses out there to keep her going.