Not sure why you keep posting stuff that is easily proven as being false.
Just like Captain America Black Panther is not a person its a mantle. And just like Captain America a mantle that has been used by others in both the comics and even the MCU. This has been explained by others. So yes you can market and sell a Black Panther movie without T'Challa, as shown in all the trailers. Because T'Challa, while a fan favorite character, has not and will not be the only Black Panther in the MCU.
The only question remains is whether Marvel will eventually recast T'Challa or not. Based on their current stance the answer is no, but it remains to be seen if that stance will change or not as the years pass.