The answer is simple, Larian owes their big success with BG3 entirely to bear sex, not story, world building (although the name Baldurs Gate helped) or characters. You can see this for example in the first threads that sprung up on this board after the announcement were about asking for more sex.
So to repeat the BG3 success as Larian stated they want to they have to add more sex and they added those scenes to the trailer to ensure their fans that they will porn it up more.
